army240
03-19-2010, 07:52 PM
Hello fellow Zilvian!
I see a lot of people in here with big electrical problems. I have some experience in electrical diagnosis, and I thought I’d share with you guys. I’ll cover some basic and advance electrical diagnosis technique, as well as how to properly use a DMM(Digital MultiMeter).
First of all, let’s talk about Diagnosis…
In the book Automotive Technology, 5th Edition, diagnosis “is a way of looking at systems that are not functioning properly and finding out why, through an understanding of the purpose and operation of the system”. Also, “diagnosis is not guessing, and it is more than following a series of inter-related step in order to find the solution to a specific problem.”
So, to simplify that, you need to know how a system works before actually working on it. THIS IS THE MOST IMPORTANT STEP!!! How the hell will you repair something that you don’t even know how it works?!? I’m not talking about “When I turn my lights on, I can see in front of my car!” It’s more like “When I turn my lights on, the power goes from this point to this point, then activate the relay X, giving ground to wire Y…” I will never say it enough to people: study electrical plans. Then you can take some logical step to isolate the problem, and then fix the situation. Ok, I think I made myself clear on that!
Now, let me ask a question… What does a component need to function? Basic answer is: Voltage and Ground. So before throwing part on your car for nothing, always check that. A light bulb doesn’t work? Yeah, it’s easy to see the filament is broken and they are cheap, but what about your nice LED brake lights on your 2010 car? Well, they work the same way, they need voltage and good ground… so you can easily test them if they don’t work.
There are basically 5 different problems that can occur with electricity.
Open wire or component
High Resistance
Short to Voltage(power)
Short to Ground
Shorted Component
I’ll explain them briefly.
1. The open wire is the most common one… a broken wire. The voltage or ground will stop where the wire is broken, and no voltage or ground will be supplied to the component. The component will then just won’t work at all. Also, remember that the component itself could be open.
2. The excessive resistance work in the same ways… there is too much resistance in your circuit, therefore not enough voltage goes to your component. There is something called the Ohms Law. I’ll be really quick on that… It’s the relation between the voltage(E), the current(I) and the resistance(R). E=IR. So if your car works on 12V, and a light bulb have 3 ohms of resistance, the current circuit will be 4 amps. In a series circuit, all the resistances are added to do the total resistance. Also, in a series circuit, the current amount is the same in all point of the circuit. So imagine I’ve got corrosion inside a terminal (most commonly cause of resistance in a circuit) that takes 3ohms. The total of resistance will be 6 Ohms (3 ohms for the light + 3 ohms for corrosion). So the total amount of current will be 2 amps (12/6=2). Voltage drop is the amount of voltage a component takes. The formula is IxR. So I’ve got 2 amps in my circuit, my light bulb have 3 ohms… voltage drop will be 6V… So my light bulb have only 6 volt for it! It will light dimly, if it doesn’t light up at all… I’ve made this pretty complicated I think… but it’s interesting to know why resistance affect voltage. The effect of this could result in lights not very bright, slow operation of something (like blower fans), etc…
3. The short to voltage is really fun… and very easy to explain… the insulation of the wire is not there, and it touch some 12V source. This is what happen when you rub your harness with your tires (yes, I’m talking about FITMEEEENT) and your windows goes down when you start your wiper (just an example like this).
4. The short to ground is the one that blow fuses. It happens when the insulation of the wire is not there anymore, and the wire is touching the ground. This one sucks… but is easy to diagnose. I’ll enter this subject later!
5. Shorted Component happens when the component itself has no more resistance in it, and let passes the entire voltage trough it… A TPS that you would get 5V out could be results of it.
I think this is clear enough. Now, I’ll explain to you how a DMM works.
A lot of people don’t use their DMM correctly, without knowing it. They can seem easy to use, but you can get fooled by them… I’ll cover how to properly calculate voltage and resistance.
To calculate voltage, you need to connect the red probe to a voltage source, and the black probe to a good known ground (battery is the best!). You put your DMM on Voltage, and then you check the reading. It’s as this simple. Here’s an example.
http://img708.imageshack.us/img708/9158/12v.jpg (http://img708.imageshack.us/i/12v.jpg/)
This is the very basics. You can also calculate the Voltage Drop. The Voltage Drop is the amount of voltage that a component takes. It’s calculated as E=IR. In the example, we have 2 ohms and 2 amps. So 2x2 = 4V! Each resistance takes 4V.
http://img248.imageshack.us/img248/4271/64279451.jpg (http://img248.imageshack.us/i/64279451.jpg/)
You can also add up voltage drop. Here’s an example:
http://img52.imageshack.us/img52/442/28042945.jpg (http://img52.imageshack.us/i/28042945.jpg/)
I’m pretty sure you are all wondering why I’m telling you all that stuff… further in the post, you will understand…
I’ll show you how to check resistance and continuity in the circuit, with a DMM.
The most important thing you need to know is: ALWAYS DISCONNECT THE POWER SOURCE BEFORE CHECKING RESISTANCE AND CONTINUITY. If you forgot to do that, you’ll reading won’t be accurate, and you could damage your DMM. It can be done by taking of the fuse or breaker that power the circuit, or simply disconnecting the negative post of the battery. The second most important thing is : ALWAYS ISOLATE YOUR CIRCUIT. If you don’t do that, you will have an inaccurate reading. When you put your DMM, it send a small electric current from the red probe, and check how much current get back to the black probe. If your probes aren’t touching each other, or aren’t connected in a circuit, the DMM will indicate OL. OL means Out of Limits. So either your scale is to low (you want to check a 1K ohms resistance on 100 ohms scale), or there is a problem in the circuit (that I’ll talk about later, don’t be scared).
Here’s an example:
http://img297.imageshack.us/img297/2438/res2ohms.jpg (http://img297.imageshack.us/i/res2ohms.jpg/)
This is pretty simple again…
Now let’s continue with continuity. Most DMM are equipped with a continuity check position, which does a sound when continuity exists. Most DMM also beep only with a resistance lower than 100 ohms. Also the DMM continuity check is only on a scale of 400 ohms. Over 400 it will display OL. So, you should use this feature only if you are sure that there is almost 0 resistance in the circuit… like finding a wire in a harness, between connector. DO NOT TRY TO CALCULATE RESISTANCE ON THE CONTINUITY CHECK MODE.
Here’s some example…
http://img717.imageshack.us/img717/1927/cont50.jpg (http://img717.imageshack.us/i/cont50.jpg/)
In the first example, we can hear the DMM Beep, because the resistance is fewer than 100 Ohms. It also indicate the correct resistance too… we can see that the guy properly disconnected the power source and isolated the circuit.
http://img532.imageshack.us/img532/1047/cont250.jpg (http://img532.imageshack.us/i/cont250.jpg/)
In this one, the DMM doesn’t beep, because the resistance is over 100 Ohms, but it still indicate the resistance value.
http://img202.imageshack.us/img202/3930/cont450.jpg (http://img202.imageshack.us/i/cont450.jpg/)
In the last one, OL is displayed, and no beep is heard. This is because the resistance is over 400 Ohms.
Note that there could be some differences in the value were it beep or not... all brands are differents... but this is the basic stuff.
Wow, that’s some interesting stuff right? Hehe… Now, let’s begin with real tests!
You remember the different type of fault you can encounter? If no, go back to the beginning, and read them again… Ok now? There are some tests you can do to find an open wire. First you can do a resistance or continuity check.
http://img411.imageshack.us/img411/918/openwire2.jpg (http://img411.imageshack.us/i/openwire2.jpg/)
First of all, I disconnect my power source (fuse, connector), then probe trought the entire circuit… My DMM displays OL, because the circuit is not complete, then it can’t calculate the resistance. So now, we know that we have an open wire.
http://img710.imageshack.us/img710/6918/openwire3.jpg (http://img710.imageshack.us/i/openwire3.jpg/)
Now, I proceed step by step… I disconnect parts of the circuit, and test them… in this example, the reading is 0 ohm, so this part of the circuit is ok.
http://img682.imageshack.us/img682/7593/openwirefound.jpg (http://img682.imageshack.us/i/openwirefound.jpg/)
You continue until you found the part that is open.
The key of this process is really to go step by step, and to know what kind of reading you should get… The second method is the voltage one.
http://img37.imageshack.us/img37/7356/openwirevolt.jpg (http://img37.imageshack.us/i/openwirevolt.jpg/)
With that method, you check for voltage… if you have voltage supply, your wire is ok!
http://img253.imageshack.us/img253/4891/openwire8v.jpg (http://img253.imageshack.us/i/openwire8v.jpg/)
Again, you still have voltage. Notice that the voltage didn’t drop… It’s because the voltage isn’t “consumed”, because it don’t have ground… so we have battery voltage!
http://img411.imageshack.us/img411/1442/openwirevfound.jpg (http://img411.imageshack.us/i/openwirevfound.jpg/)
Here we go; we found which part of the circuit is broken, because I don’t have anymore voltage in my circuit!
Let’s continue with the cool high resistance fault… like I said earlier, a high resistance could be caused by corrosion. This is probably the most common cause of resistance known to man.
http://img208.imageshack.us/img208/2608/highrestrue.jpg (http://img208.imageshack.us/i/highrestrue.jpg/)
First step, you need to find what kind of fault you have… so you probe the entire circuit… here we clearly see that there is too much resistance.
http://img12.imageshack.us/img12/1175/highres3.jpg (http://img12.imageshack.us/i/highres3.jpg/)
So the next steps are pretty much the same like finding an open… so you isolate parts of you circuit, to find where the resistance is. We can see here that there is no resistance, therefore this part is ok.
http://img138.imageshack.us/img138/1406/highres4.jpg (http://img138.imageshack.us/i/highres4.jpg/)
Ahhh, here’s the problem. So you correct the condition. Like the open, keep in mind that you can have a high resistance in the component itself. There is another method to find resistance, which is the voltage drop method… but I’m not going to cover that, because it’s not used very often. It’s mostly used with air bags.
The third fault, the short to voltage, is very easy to diagnose. I will not explain that with drawing, only words. This type of fault doesn’t happen very frequently. Imagine your headlights aren’t turning off. Well, it’s because there voltage to them all the time. So you disconnect part of the circuit, and probe for voltage with the circuit isolated. The red probe on the wire and the black probe on a good ground. As you may know, there shouldn’t be any voltage in a wire, if this wire is disconnected on both ends.
Shorts to ground happen more frequently.
http://img39.imageshack.us/img39/1842/shtog.jpg (http://img39.imageshack.us/i/shtog.jpg/)
This is what happens with a short to ground. The fuse is blown, because there is direct continuity to the ground. I need to warn you of something. This is a fault that connects in parallel. So the circuit could work, depends of where the short is, and the type of circuit.
There is two ways to diagnose this. The resistance (or continuity) check and the voltage one.
http://img135.imageshack.us/img135/5265/shtogfoundv.jpg (http://img135.imageshack.us/i/shtogfoundv.jpg/)
The first method I’ll tell you is the voltage one… Like I said, a short to ground is a wire that has continuity to the ground. So this wire itself is now a ground! So you put your red probe to the positive post of the battery, and you probe with the black probe in the circuit. There is a small mistake in my drawing… I didn’t properly isolate my circuit (it was on purpose). So if you do that, and you see battery voltage displayed on your DMM, well this wire is a ground or is short to ground!
http://img163.imageshack.us/img163/1589/shtogres.jpg (http://img163.imageshack.us/i/shtogres.jpg/)
The next method is the resistance or continuity check… I prefer using resistance, because there could be a small resistance, and on the continuity check, you know it’s only good for 400 ohms… but it’s just my method of working. So basically, what you do in that method is to put the black probe on the ground, and you probe with the red one in the circuit. If there is 0 or almost no resistance, this wire is short to ground!
Now with the last fault, a shorted component.
http://img299.imageshack.us/img299/5324/shortedres.jpg (http://img299.imageshack.us/i/shortedres.jpg/)
Let’s say that the first resistance in the circuit above is shorted. The easiest method is to check is resistance… if there is none, well it’s shorted. That’s it! You could also check how much voltage there is after the resistance… if you have full voltage, well it’s shorted. It happens sometimes with TPS, and coolant temperature sensor.
This is why automotive constructors don’t put TPS voltage of 0V to 5V. It’s more like 0.5V to 4.5V, so if you have a signal of 0V, you know your TPS is open, and if you have 5V output, well it’s shorted!
Anyway, I hope that kinda help you. I know this can seems complicated. I don’t expect you to learn that, or put it to use. But if you took the time to read this, your test will be more accurate, and conclusive. Don’t forget that there are a lot of people in here that tries to help you with your cars. So when we ask you to do a test, from now on, you will do that test properly.
If anybody has comments or questions, feel free to ask, I will be more than glad to help you!
Frank
I see a lot of people in here with big electrical problems. I have some experience in electrical diagnosis, and I thought I’d share with you guys. I’ll cover some basic and advance electrical diagnosis technique, as well as how to properly use a DMM(Digital MultiMeter).
First of all, let’s talk about Diagnosis…
In the book Automotive Technology, 5th Edition, diagnosis “is a way of looking at systems that are not functioning properly and finding out why, through an understanding of the purpose and operation of the system”. Also, “diagnosis is not guessing, and it is more than following a series of inter-related step in order to find the solution to a specific problem.”
So, to simplify that, you need to know how a system works before actually working on it. THIS IS THE MOST IMPORTANT STEP!!! How the hell will you repair something that you don’t even know how it works?!? I’m not talking about “When I turn my lights on, I can see in front of my car!” It’s more like “When I turn my lights on, the power goes from this point to this point, then activate the relay X, giving ground to wire Y…” I will never say it enough to people: study electrical plans. Then you can take some logical step to isolate the problem, and then fix the situation. Ok, I think I made myself clear on that!
Now, let me ask a question… What does a component need to function? Basic answer is: Voltage and Ground. So before throwing part on your car for nothing, always check that. A light bulb doesn’t work? Yeah, it’s easy to see the filament is broken and they are cheap, but what about your nice LED brake lights on your 2010 car? Well, they work the same way, they need voltage and good ground… so you can easily test them if they don’t work.
There are basically 5 different problems that can occur with electricity.
Open wire or component
High Resistance
Short to Voltage(power)
Short to Ground
Shorted Component
I’ll explain them briefly.
1. The open wire is the most common one… a broken wire. The voltage or ground will stop where the wire is broken, and no voltage or ground will be supplied to the component. The component will then just won’t work at all. Also, remember that the component itself could be open.
2. The excessive resistance work in the same ways… there is too much resistance in your circuit, therefore not enough voltage goes to your component. There is something called the Ohms Law. I’ll be really quick on that… It’s the relation between the voltage(E), the current(I) and the resistance(R). E=IR. So if your car works on 12V, and a light bulb have 3 ohms of resistance, the current circuit will be 4 amps. In a series circuit, all the resistances are added to do the total resistance. Also, in a series circuit, the current amount is the same in all point of the circuit. So imagine I’ve got corrosion inside a terminal (most commonly cause of resistance in a circuit) that takes 3ohms. The total of resistance will be 6 Ohms (3 ohms for the light + 3 ohms for corrosion). So the total amount of current will be 2 amps (12/6=2). Voltage drop is the amount of voltage a component takes. The formula is IxR. So I’ve got 2 amps in my circuit, my light bulb have 3 ohms… voltage drop will be 6V… So my light bulb have only 6 volt for it! It will light dimly, if it doesn’t light up at all… I’ve made this pretty complicated I think… but it’s interesting to know why resistance affect voltage. The effect of this could result in lights not very bright, slow operation of something (like blower fans), etc…
3. The short to voltage is really fun… and very easy to explain… the insulation of the wire is not there, and it touch some 12V source. This is what happen when you rub your harness with your tires (yes, I’m talking about FITMEEEENT) and your windows goes down when you start your wiper (just an example like this).
4. The short to ground is the one that blow fuses. It happens when the insulation of the wire is not there anymore, and the wire is touching the ground. This one sucks… but is easy to diagnose. I’ll enter this subject later!
5. Shorted Component happens when the component itself has no more resistance in it, and let passes the entire voltage trough it… A TPS that you would get 5V out could be results of it.
I think this is clear enough. Now, I’ll explain to you how a DMM works.
A lot of people don’t use their DMM correctly, without knowing it. They can seem easy to use, but you can get fooled by them… I’ll cover how to properly calculate voltage and resistance.
To calculate voltage, you need to connect the red probe to a voltage source, and the black probe to a good known ground (battery is the best!). You put your DMM on Voltage, and then you check the reading. It’s as this simple. Here’s an example.
http://img708.imageshack.us/img708/9158/12v.jpg (http://img708.imageshack.us/i/12v.jpg/)
This is the very basics. You can also calculate the Voltage Drop. The Voltage Drop is the amount of voltage that a component takes. It’s calculated as E=IR. In the example, we have 2 ohms and 2 amps. So 2x2 = 4V! Each resistance takes 4V.
http://img248.imageshack.us/img248/4271/64279451.jpg (http://img248.imageshack.us/i/64279451.jpg/)
You can also add up voltage drop. Here’s an example:
http://img52.imageshack.us/img52/442/28042945.jpg (http://img52.imageshack.us/i/28042945.jpg/)
I’m pretty sure you are all wondering why I’m telling you all that stuff… further in the post, you will understand…
I’ll show you how to check resistance and continuity in the circuit, with a DMM.
The most important thing you need to know is: ALWAYS DISCONNECT THE POWER SOURCE BEFORE CHECKING RESISTANCE AND CONTINUITY. If you forgot to do that, you’ll reading won’t be accurate, and you could damage your DMM. It can be done by taking of the fuse or breaker that power the circuit, or simply disconnecting the negative post of the battery. The second most important thing is : ALWAYS ISOLATE YOUR CIRCUIT. If you don’t do that, you will have an inaccurate reading. When you put your DMM, it send a small electric current from the red probe, and check how much current get back to the black probe. If your probes aren’t touching each other, or aren’t connected in a circuit, the DMM will indicate OL. OL means Out of Limits. So either your scale is to low (you want to check a 1K ohms resistance on 100 ohms scale), or there is a problem in the circuit (that I’ll talk about later, don’t be scared).
Here’s an example:
http://img297.imageshack.us/img297/2438/res2ohms.jpg (http://img297.imageshack.us/i/res2ohms.jpg/)
This is pretty simple again…
Now let’s continue with continuity. Most DMM are equipped with a continuity check position, which does a sound when continuity exists. Most DMM also beep only with a resistance lower than 100 ohms. Also the DMM continuity check is only on a scale of 400 ohms. Over 400 it will display OL. So, you should use this feature only if you are sure that there is almost 0 resistance in the circuit… like finding a wire in a harness, between connector. DO NOT TRY TO CALCULATE RESISTANCE ON THE CONTINUITY CHECK MODE.
Here’s some example…
http://img717.imageshack.us/img717/1927/cont50.jpg (http://img717.imageshack.us/i/cont50.jpg/)
In the first example, we can hear the DMM Beep, because the resistance is fewer than 100 Ohms. It also indicate the correct resistance too… we can see that the guy properly disconnected the power source and isolated the circuit.
http://img532.imageshack.us/img532/1047/cont250.jpg (http://img532.imageshack.us/i/cont250.jpg/)
In this one, the DMM doesn’t beep, because the resistance is over 100 Ohms, but it still indicate the resistance value.
http://img202.imageshack.us/img202/3930/cont450.jpg (http://img202.imageshack.us/i/cont450.jpg/)
In the last one, OL is displayed, and no beep is heard. This is because the resistance is over 400 Ohms.
Note that there could be some differences in the value were it beep or not... all brands are differents... but this is the basic stuff.
Wow, that’s some interesting stuff right? Hehe… Now, let’s begin with real tests!
You remember the different type of fault you can encounter? If no, go back to the beginning, and read them again… Ok now? There are some tests you can do to find an open wire. First you can do a resistance or continuity check.
http://img411.imageshack.us/img411/918/openwire2.jpg (http://img411.imageshack.us/i/openwire2.jpg/)
First of all, I disconnect my power source (fuse, connector), then probe trought the entire circuit… My DMM displays OL, because the circuit is not complete, then it can’t calculate the resistance. So now, we know that we have an open wire.
http://img710.imageshack.us/img710/6918/openwire3.jpg (http://img710.imageshack.us/i/openwire3.jpg/)
Now, I proceed step by step… I disconnect parts of the circuit, and test them… in this example, the reading is 0 ohm, so this part of the circuit is ok.
http://img682.imageshack.us/img682/7593/openwirefound.jpg (http://img682.imageshack.us/i/openwirefound.jpg/)
You continue until you found the part that is open.
The key of this process is really to go step by step, and to know what kind of reading you should get… The second method is the voltage one.
http://img37.imageshack.us/img37/7356/openwirevolt.jpg (http://img37.imageshack.us/i/openwirevolt.jpg/)
With that method, you check for voltage… if you have voltage supply, your wire is ok!
http://img253.imageshack.us/img253/4891/openwire8v.jpg (http://img253.imageshack.us/i/openwire8v.jpg/)
Again, you still have voltage. Notice that the voltage didn’t drop… It’s because the voltage isn’t “consumed”, because it don’t have ground… so we have battery voltage!
http://img411.imageshack.us/img411/1442/openwirevfound.jpg (http://img411.imageshack.us/i/openwirevfound.jpg/)
Here we go; we found which part of the circuit is broken, because I don’t have anymore voltage in my circuit!
Let’s continue with the cool high resistance fault… like I said earlier, a high resistance could be caused by corrosion. This is probably the most common cause of resistance known to man.
http://img208.imageshack.us/img208/2608/highrestrue.jpg (http://img208.imageshack.us/i/highrestrue.jpg/)
First step, you need to find what kind of fault you have… so you probe the entire circuit… here we clearly see that there is too much resistance.
http://img12.imageshack.us/img12/1175/highres3.jpg (http://img12.imageshack.us/i/highres3.jpg/)
So the next steps are pretty much the same like finding an open… so you isolate parts of you circuit, to find where the resistance is. We can see here that there is no resistance, therefore this part is ok.
http://img138.imageshack.us/img138/1406/highres4.jpg (http://img138.imageshack.us/i/highres4.jpg/)
Ahhh, here’s the problem. So you correct the condition. Like the open, keep in mind that you can have a high resistance in the component itself. There is another method to find resistance, which is the voltage drop method… but I’m not going to cover that, because it’s not used very often. It’s mostly used with air bags.
The third fault, the short to voltage, is very easy to diagnose. I will not explain that with drawing, only words. This type of fault doesn’t happen very frequently. Imagine your headlights aren’t turning off. Well, it’s because there voltage to them all the time. So you disconnect part of the circuit, and probe for voltage with the circuit isolated. The red probe on the wire and the black probe on a good ground. As you may know, there shouldn’t be any voltage in a wire, if this wire is disconnected on both ends.
Shorts to ground happen more frequently.
http://img39.imageshack.us/img39/1842/shtog.jpg (http://img39.imageshack.us/i/shtog.jpg/)
This is what happens with a short to ground. The fuse is blown, because there is direct continuity to the ground. I need to warn you of something. This is a fault that connects in parallel. So the circuit could work, depends of where the short is, and the type of circuit.
There is two ways to diagnose this. The resistance (or continuity) check and the voltage one.
http://img135.imageshack.us/img135/5265/shtogfoundv.jpg (http://img135.imageshack.us/i/shtogfoundv.jpg/)
The first method I’ll tell you is the voltage one… Like I said, a short to ground is a wire that has continuity to the ground. So this wire itself is now a ground! So you put your red probe to the positive post of the battery, and you probe with the black probe in the circuit. There is a small mistake in my drawing… I didn’t properly isolate my circuit (it was on purpose). So if you do that, and you see battery voltage displayed on your DMM, well this wire is a ground or is short to ground!
http://img163.imageshack.us/img163/1589/shtogres.jpg (http://img163.imageshack.us/i/shtogres.jpg/)
The next method is the resistance or continuity check… I prefer using resistance, because there could be a small resistance, and on the continuity check, you know it’s only good for 400 ohms… but it’s just my method of working. So basically, what you do in that method is to put the black probe on the ground, and you probe with the red one in the circuit. If there is 0 or almost no resistance, this wire is short to ground!
Now with the last fault, a shorted component.
http://img299.imageshack.us/img299/5324/shortedres.jpg (http://img299.imageshack.us/i/shortedres.jpg/)
Let’s say that the first resistance in the circuit above is shorted. The easiest method is to check is resistance… if there is none, well it’s shorted. That’s it! You could also check how much voltage there is after the resistance… if you have full voltage, well it’s shorted. It happens sometimes with TPS, and coolant temperature sensor.
This is why automotive constructors don’t put TPS voltage of 0V to 5V. It’s more like 0.5V to 4.5V, so if you have a signal of 0V, you know your TPS is open, and if you have 5V output, well it’s shorted!
Anyway, I hope that kinda help you. I know this can seems complicated. I don’t expect you to learn that, or put it to use. But if you took the time to read this, your test will be more accurate, and conclusive. Don’t forget that there are a lot of people in here that tries to help you with your cars. So when we ask you to do a test, from now on, you will do that test properly.
If anybody has comments or questions, feel free to ask, I will be more than glad to help you!
Frank