Wiring: DTRLs and electric gauges

[SHIFT_*grind*]

I hadn't wired my DTRLs or gauges yet, so since the gauge lamps and DTRLs are kinda related as to when I want them to come on, I figured I'd wire them all at once.

I want the DTRLs, and gauge lighting, to come on with the parking lights/headlights.

I want the electric gauges to come on with the ignition (accessory would be fine too, just as long as they're not constantly on).

(DISCLAIMER: I suck at wiring diagrams.)

http://smg.photobucket.com/albums/v245/bigjay00213/wiring1.jpg

Arrows indicate wiring, and direction of current flow. I could possibly have the direction of current flow on the IGN ON wire wrong (I'm thinking it flows *away* from the ignition switch). I did not depict the wiring going from the temperature/pressure senders to the gauges. A 10A fuse should be enough for the low amperage that DTRLs pull, but I have the gauges and lighting on there as well (and I may add an electric fan to the ignition relay) so I went with a 30A fuse.


Tell me what's wrong with this diagram.

[g6civcx]

That won't work. There a couple of things wrong with it.


Arrows indicate wiring, and direction of current flow. I could possibly have the direction of current flow on the IGN ON wire wrong (I'm thinking it flows *away* from the ignition switch).

This explanation is more info than you need to make it work so peruse at your discretion.

You need to understand how electricity works. Electrons are negatively charged carriers. Protons are positively charged carriers.

Generally, when the numbers of electrons = number of protons, you get a neutral charge. When you have an excess of electrons, you get a (-) charge. When you have a deficiency in electrons, you have a (+) charge.

The difference is that electrons are much much smallers than protons. So when electrical current is flowing from one area to another, it's actually the electrons that are flowing from an area of electron excess (ground) to an area of electron deficiency (+ terminal).


So the (+) terminal has a deficiency in electrons. This creates an electric potential in that the (+) terminals want to suck in electrons.

The (-) terminal or ground has an abundance of free electrons. So when you hook (+) to ground, the voltage at (+) induced by a deficiency in electrons creates an electrical potential that sucks electrons in from (-) or ground.


This is even more confusing because in the US, we use arrows to go from (+) to (-) to indicate the flow of electric potential, but in reality electrons flow from (-) to (+).

In other countries the arrows go the other way to indicate the direction of electron travel. Sometimes they'll even switch (+)/positive and (-)/negative labels just to make things more confusing.


This is a really simplistic view, but it's how I view electricity. I see the terminal as want to suck in electrons, and I see ground as having lots of electrons. So in order for a current to work, you need to connect ground to the accessory then to the battery terminal with electron deficiency.

Confused yet? :confused:


The biggest problems I see with your diagram are as follows:

1. The gauge lamps should not be hooked to DTRL power wires like that. You need to hook the gauge lamp straight to ground. If you hook it up like that, you will get current collision and the lamps may burn = fire.

Generally speaking, once current passes through an accessory, it's considered dirty current and needs to go straight to ground. You should not piggyback current onto another accessory before returning to ground.

2. What is "harness" and "ignition harness"? These should be ground. When you apply power and ground to pins 85/86 in any order, it will connect pins 30 and 87.

3. Using a 30A fuse for both lines is not a good idea. You need to separate the lines out. For example, if the DTRL pulls 25A and the gauges only pull 5A, it will not be enough to break the fuse, but it will burn the lights.

Run a separate wire from battery to 10A to DRTL relay. Run another wire from battery to 10A to gauge relay. Don't tie them together like that.

4. The dimmer switch doesn't control the lights. The dimmer switch supplies variable resistance to adjust brightness of the interior lights. You need to tap a parking light wire.

5. Keep in mind that IGN ON gives power when the key is turned to ON or ST. ACC only gives power when the key is turned to ACC or ON, but not at ST. Keep that in mind if you want to see the gauges during starter crank.


Good effort but try again.

[SHIFT_*grind*]

One million thanks. I appreciate it a lot man, that makes things a lot more clear. :)

[g6civcx]

Do you want to try again or do you want to bribe me to make a diagram for you? :)

[cotbu]

Diagram diagram diagram....
I can see myself linking this page in someones post, 2 weeks from now!

[SHIFT_*grind*]

Do you want to try again or do you want to bribe me to make a diagram for you? :)

I'll give it another shot, all my bribe money is going to parts these days ;)

[SHIFT_*grind*]

OK, take two.

http://smg.photobucket.com/albums/v245/bigjay00213/wiring2.jpg

Now, will this work, having one main wire coming off the negative battery terminal that all the accessories ground to? Or do I need to separate out the wires like this:

http://smg.photobucket.com/albums/v245/bigjay00213/wiring3.jpg

I had thought of using the dimmer switch wire since it only gets power when the parking lights/headlights are turned on; I currently only have a boost gauge, and the lamp is wired to the dimmer switch.

(Also, I thought it'd be cleaner to ground everything back to the battery rather than various metal surfaces in the cabin/engine bay)

[g6civcx]

The first diagram looks ok.

Questions:

1. Why do you have 2 gauge lamps?
2. What DTRL are you using?
3. What gauges are you using? How much max current can each gauge handle? If you don't know, ask the vendor or manufacturer.

Both diagrams are okay provided you ground them all to the same point.

The dimmer switch has 2 sets of wires: illumination and dimmer control circuit. It is weird. You should not use it to pull current for anything.

Use the parking light wire. It's a cleaner current.

I recommend redoing your boost gauge wiring as well.

The gauges definitely should be grounded to a common point. Lights and accessories don't really matter if they flicker a bit, but sensitive electronics like gauges and radio need clean grounding to work correctly.

[SHIFT_*grind*]

1.) One gauge lamp for water temp, one for oil pressure (just the little light bulbs that come with the gauges). I'll redo my boost gauge lamp as well, so that'll make three.
2.) Canadian market DTRLs. I could wire them up with a switch, or to act like actual daytime running lights, but I'm fine just having them on with the parking lights.
3.) Autometer oil pressure and water temp. I just checked the install instructions online, they recommend a 4 amp fuse per gauge.

I didn't know that about the dimmer switch, I'll definitely pull my boost gauge lamp off of there.

[g6civcx]

1.) One gauge lamp for water temp, one for oil pressure (just the little light bulbs that come with the gauges). I'll redo my boost gauge lamp as well, so that'll make three.

With the light bulbs, you can probably piggyback all 3 onto the parking light wire and still be ok. They're small so they probably won't draw much current. Even if the bulb blows you can put a new one in no sweat.

Just make sure you use 16AWG wire. That way, if the wire shorts to ground it will blow the fuse before the wire burns. Using a really small wire + short to ground = no fuse blown but fire.


2.) Canadian market DTRLs. I could wire them up with a switch, or to act like actual daytime running lights, but I'm fine just having them on with the parking lights.

Okay good. If you want to wire them up like stock then we have a lot more wiring to do.

It's much easier to do a switch or turn on with parking lights.

The candian DTRLs are really low intensity so they both pull 10A at most.


3.) Autometer oil pressure and water temp. I just checked the install instructions online, they recommend a 4 amp fuse per gauge.

Put a 5A fuse in front of each gauge if you want to be safe, or leave out the 5A fuse if you don't mind blowing the gauge.

I didn't know that about the dimmer switch, I'll definitely pull my boost gauge lamp off of there.

The illumination control switch provides variable resistance to ground to all the interior lights. More ground = brighter. Less ground = dimmer.

The switch also has a light bulb that runs off the parking light wire.

[SHIFT_*grind*]

The switch also has a light bulb that runs off the parking light wire.

Ahhh, maybe that's what I'm tapped off of for the boost gauge lamp.

Is 14 gauge sufficient for the wires to/from the 10A fuses, and also going to/from the accessories? (except the "main ground wire" which would definitely be bigger) I've got like 100 feet of it.

[g6civcx]

Is 14 gauge sufficient for the wires to/from the 10A fuses, and also going to/from the accessories? (except the "main ground wire" which would definitely be bigger) I've got like 100 feet of it.

14AWG should be ok for 10A max, although for the ground wire I would go with 12AWG since you're tying both the gauges and the lights together.

[SHIFT_*grind*]

Yeah I was thinking, like, 10AWG for the ground wire to be safe.

Thanks again for all the help =D