Relay wiring question

[AsleepAltima]

ok, i rewired my fuel pump, actually, wired in a relay to send a full 12 volts to the hot side of the pump using the 12 volt signal wire from the fuel pump harness. worked like a charm except for one problem: when i turn the ignition off, the relay still supplies 12 volts to the electrical system and the car continues to run. if i put it in gear and kill it, the voltage goes away and the harness is off. i tried using a 4 prong relay and a 5 prong and it does the same thing. i even used a nissan headlight relay off of my altima parts car and it does the same thing - continues to run with the key "off".

anyone with a similar problem? i guess i could wire in a switch, but i want this to be turn-key and not have to hit an additional switch every time i get into the car.

[godsmack]

its wired wrong. basically you want the switched part to be the voltage for the fuel pump. and the normaly closed section to be the power from the key. so key power - nc relay. nc other side - continue circuit. 12v signal wire - no relay -/- coming out of there go to fuel pump.

[AsleepAltima]

i tried that. same result. followed this:

http://www.greenhulk.net/forums/attachment.php?attachmentid=210903&stc=1&d=1282264526

and tried switching the wires around. basically, the relay was supplying the power until i interrupted it. once i did that, it effectively killed the circuit. i just said f it and wired in a toggle and hid it in the center console. :/

[WIKID S4TEEN]

Shouldn't the ignition switch be shuting the power off to the relay?
Looks like you have the battery direct to relay.

[AsleepAltima]

Shouldn't the ignition switch be shuting the power off the relay?
Looks like you have the battery direct to relay.it is but only the relay power is direct to battery. the switched part goes to the fuel pump.

i was just on a different forum reading about the same thing and they said the problem comes from the ecu trigger wire being negatively grounded, thats why the relay continues to send power. makes sense i guess.

[WIKID S4TEEN]

Actually, it doesn't. I can help you, if you're willing to post pictures of the connections and take voltage readings??

[godsmack]

Learn how a relay works. the switched part will close when power is applied to the other circuit. the switched part is closed by a magnetic field from the power. so if you have constant power there the switched part will close the circuit. you will need to jump into your ignition power somewhere if you want it powered by the ignition.

[godrifttoday]

i tried that. same result. followed this:

http://www.greenhulk.net/forums/attachment.php?attachmentid=210903&stc=1&d=1282264526

and tried switching the wires around. basically, the relay was supplying the power until i interrupted it. once i did that, it effectively killed the circuit. i just said f it and wired in a toggle and hid it in the center console. :/

86 is the signal wire to activte or turn off the switch.. what are u using to send power to that part of the swtich? u can also use a toggle switch if u like?

the diagram is correct just get 12 volts to 86 and when ever you turn off the car it shuts off...

[godsmack]

on the side of the relay there should be a wiring diagram. not all relays are going to be the same. look at the diagram on the relay. but it seems to me that where ever you broke the circuit and it shut off, switch that wire with an ignition wire (one that only has power when the key is in the "on" position) and you will be fine.

[AsleepAltima]

i do know that i used the ignition source according to the diagram. two different relays did the same thing. when you cut power to the relay - by pulling any of the wires off - it shuts off and then it doesnt have any power anywhere except for the battery source, of course, just like its supposed to. im using a different relay now than the bosch style relay. im using one of the black nissan relays that nissan likes to use for headlights in the altima and maxima. ill take a pic of it and describe where each wire is going. if i did something wrong, maybe you guys can see it.

[Broadfield]

As some have said, simply run ignition power to pin 86. It doesn't even need to be high current since it's only triggering the relay... it can be less than 1 amp. It can come from the radio, the fuse box, the ignition harness etc.

[AsleepAltima]

im not using that relay anymore, im using the nissan one thats numbered 1-5.

like this:

http://img.photobucket.com/albums/v610/AsleepAltima/20120711_222134.jpg

and i have it wired like this: 1 - ground, 2 - 12v ignition, 3 - Batt, 5 - fp power

should 2 be battery?

[WIKID S4TEEN]

It shouldn't matter but I'd wired
1) to ignition switch or switch (+12vdc)
2) ground
The rest is correct.

[AsleepAltima]

2 does go to ignition.

[WIKID S4TEEN]

That should work. If the pump keeps running after you remove the key, you have a stuck relay or the power from the ignition is NOT turning off.
Next step is voltage reading.

[AsleepAltima]

That should work. If the pump keeps running after you remove the key, you have a stuck relay or the power from the ignition is NOT turning off.
Next step is voltage reading.i tried 2 different relays and can feel the relay clicking off and on when i have my wife turn the key. the fuel pump voltage increases accordingly too. if i turn the key off and then remove one of the power wires, the engine shuts down like its supposed to and voltage is gone. thats why im stumped.

the fuel pump harness only has 1 wire that is 12v ignition switched. its the only i can go with just like theres only 1 wire that feeds the pump its power. it makes no sense that its working this way. the only thing i can think of that SHOULD remove power when the key is turned off is to physically cut the fuel pump power wire and leave it connected pump side to the relay, so that its not back feeding to the car side of the harness. do you think that could be the issue? i left it intact because i read a thread somewhere here that said to leave the wiring intact and just add the relay so that the ecu can continue to control the pump while the engine isnt running.

[JDMRIDDAZ]

get a real aftermarket relay...
i kno u can use the nissan ones but damn
ur diagram is not the way i do it...but iam not saying its incorrect
and u should be using a test light to diagnose...Google Image Result for http://site.unbeatablesale.com/img099/egle5060.gif (http://www.google.com/imgres?q=power+probe+gifs&hl=en&client=firefox-a&hs=2gN&sa=X&rls=org.mozilla:en-US:official&biw=1280&bih=584&tbm=isch&prmd=imvns&tbnid=q4s32gRwMwSqJM:&imgrefurl=http://products.unbeatablesale.com/power_probe-assorted_measuring_tools_S110.php&docid=EK36-hL09UsM6M&itg=1&imgurl=http://site.unbeatablesale.com/img099/egle5060.gif&w=300&h=300&ei=if7-T5OQKIK09QSL4cCGBw&zoom=1&iact=hc&vpx=708&vpy=4&dur=3241&hovh=225&hovw=225&tx=78&ty=248&sig=108852719826419449638&page=1&tbnh=126&tbnw=153&start=0&ndsp=23&ved=1t:429,r:5,s:0,i:90)
87=12v
86=ground
85=ignition
30=fuelpump

[AsleepAltima]

the real relay was blown, that's why i'm using this one. I don't need a test light, I have a fluke. everything is wired how it should be. its gotta be something dumb. I'll try another "real" relay and try your way but I've wired it a couple different ways and same result.

[WIKID S4TEEN]

If you have fluke, no need for test light, lol.
Let's test the relay.
Take the relay out of the circuit completely.
Can you apply 12VDC to the relay coil (1&2)?
You should get continuity across 3 & 5.
and no continuity when you release the power to the coil.
Please confirm.

[AsleepAltima]

If you have fluke, no need for test light, lol.
Let's test the relay.
Take the relay out of the circuit completely.
Can you apply 12VDC to the relay coil (1&2)?
You should get continuity across 3 & 5.
and no continuity when you release the power to the coil.
Please confirm.
i bought a new relay while i was out, we can try this one and see what happens. ill use the above wiring suggestion and see what happens. that would make it 3 different relays if it does it again, lol.
oh, i actually have 2 flukes, lol.

[WIKID S4TEEN]

If it's not too late. Test the relay outside of the circuit first.
Just in case there's something wrong.

[godrifttoday]

dam dude your making this toooooo complicated

[AsleepAltima]

dam dude your making this toooooo complicated
its not complicated. its all wired, tucked, soldered and heat shrunk. all we are doing here is figuring out why its continuing to run with the key off so i can eliminate the toggle. its drivable right now. i didnt spend close to 11k on this car to be turning the fuel pump on and off with a toggle.

[AsleepAltima]

If it's not too late. Test the relay outside of the circuit first.
Just in case there's something wrong.
naw its not too late, i just got me a cold coke, ill test it before i head out to the car. :)

[AsleepAltima]

get a real aftermarket relay...
i kno u can use the nissan ones but damn
ur diagram is not the way i do it...but iam not saying its incorrect
and u should be using a test light to diagnose...Google Image Result for http://site.unbeatablesale.com/img099/egle5060.gif (http://www.google.com/imgres?q=power+probe+gifs&hl=en&client=firefox-a&hs=2gN&sa=X&rls=org.mozilla:en-US:official&biw=1280&bih=584&tbm=isch&prmd=imvns&tbnid=q4s32gRwMwSqJM:&imgrefurl=http://products.unbeatablesale.com/power_probe-assorted_measuring_tools_S110.php&docid=EK36-hL09UsM6M&itg=1&imgurl=http://site.unbeatablesale.com/img099/egle5060.gif&w=300&h=300&ei=if7-T5OQKIK09QSL4cCGBw&zoom=1&iact=hc&vpx=708&vpy=4&dur=3241&hovh=225&hovw=225&tx=78&ty=248&sig=108852719826419449638&page=1&tbnh=126&tbnw=153&start=0&ndsp=23&ved=1t:429,r:5,s:0,i:90)
87=12v
86=ground
85=ignition
30=fuelpump
same result. runs till the toggle is flipped.

[AsleepAltima]

If you have fluke, no need for test light, lol.
Let's test the relay.
Take the relay out of the circuit completely.
Can you apply 12VDC to the relay coil (1&2)?
You should get continuity across 3 & 5.
and no continuity when you release the power to the coil.
Please confirm.
confirmed. now i have a new spst relay that i just wired up the way that jdmriddaz suggested and no change. what do you think if i clip the fuel pump supply wire and connect it to directly to the relay? then it cant complete the circuit car side - only pump side.

[didderson]

It sounds like you used the wrong input/output power from your fuel pump harness. If you did this near the tank like I did, I can take some pics of the wires to use to do this correctly (AT the fuel sump plug yo). Maybe your relay pins are tripped up but it sounds like your relay coil is constantly switched, yet the output only works when the car is on. I bought a car someone did that to, drains batteries off the tiny coil being energized so fix it soon.

I mounted my relay beside/above the sump on the inner frame just made a tapped ground.

Also, I hard wired around the sump plug for the power& gnd, shits not reliable with the amperage our aftermarket pumps need.

[AsleepAltima]

It sounds like you used the wrong input/output power from your fuel pump harness. If you did this near the tank like I did, I can take some pics of the wires to use to do this correctly (AT the fuel sump plug yo). Maybe your relay pins are tripped up but it sounds like your relay coil is constantly switched, yet the output only works when the car is on. I bought a car someone did that to, drains batteries off the tiny coil being energized so fix it soon.

I mounted my relay beside/above the sump on the inner frame just made a tapped ground.
if you could do that, that would be awesome. i have no worries about it draining though - once the toggle switches it off and the engine dies, there is no voltage anywhere at the harness, regardless of toggle position. im pretty positive its wired correctly, i think the voltage being added to the harness is creating voltage elsewhere. but either way, ill take a look at your harness and compare and change, if i have to.

[KiLLeR2001]

Either you don't understand how a relay works or something is up with your ignition switch. I'd get rid of the toggle and get to the bottom of this issue. Crack open the steering column and see if voltage still exists in the IGN ON lead when power is cut off.

[AsleepAltima]

i dont understand how everyone thinks i dont understand how a relay works - it works fine. it is providing power just like it is supposed to - with a turn of the key. the problem is not getting the power to the pump - the power is there. its not shutting off that is the problem. when i test it with a multi-meter, the power is gone but the car continues to run. with the toggle momentarily switched - all power is gone - like it should be. it doesnt come back on regardless of toggle position because THERES NO INPUT VOLTAGE to the relay from the switched side of the pump harness. i understand how it works just fine.

[AsleepAltima]

and the car works fine without the new relay. you wouldnt even know there was a problem if i didnt have the wideband installed. the loss of voltage at 5k rpm is the problem. i think that pretty solidly rules out the ignition switch.

[KiLLeR2001]

Have you tried using the relay to switch ground and NOT voltage?

Hook up voltage (with fuse) directly to the power wire on the fuel pump, make ignition on trigger the relay which will ground between [87] and [30] on the relay.

So essentially you'd have:

[85] ground to chassis
[86] ign on
[87] ground to chassis
[30] to fuel pump ground wire

[AsleepAltima]

Have you tried using the relay to switch ground and NOT voltage?

Hook up voltage (with fuse) directly to the power wire on the fuel pump, make ignition on trigger the relay which will ground between [87] and [30] on the relay.

So essentially you'd have:

[85] ground to chassis
[86] ign on
[87] ground to chassis
[30] to fuel pump ground wire
i havent tried that route yet, but i will right now. thanks!

[KiLLeR2001]

Also, what type of fuel pump are you using? What size gauge wire? What fuse rating are you using? What is the total length of the circuit? What engine / chassis? All this is important and crucial information that you must take into account.

[godrifttoday]

So essentially you'd have:

[85] ground to chassis
[86] ign on
[87] ground to chassis
[30] to fuel pump ground wire


dont do that.... please dont.

[AsleepAltima]

Also, what type of fuel pump are you using? What size gauge wire? What fuse rating are you using? What is the total length of the circuit? What engine / chassis? All this is important and crucial information that you must take into account.
walbro 255, 12 gauge off of the relay, factory wiring car/harness side, at most, 16 inches long for the relay wiring - sr20 s13.

wiring off of ground, energized the relay, but there was no increase of voltage at the pump. sits at 11 volts during idle.

[KiLLeR2001]

Is there 11v at your 12gauge power wire to fuel pump initially? Or is it at 12v but when you start the car it goes down to 11v?

edit:

dont do that.... please dont.

Care to explain why? You seem to have a vast knowledge in electrical engineering. I'd love to hear the reasoning. LOL.

Btw, take a look at the FSM. You might be shocked to see a lot of the switches in our cars switch ground, and not power. Oops.

[AsleepAltima]

Is there 11v at your 12gauge power wire to fuel pump initially? Or is it at 12v but when you start the car it goes down to 11v?

edit:



Care to explain why? You seem to have a vast knowledge in electrical engineering. I'd love to hear the reasoning. LOL.

Btw, take a look at the FSM. You might be shocked to see a lot of the switches in our cars switch ground, and not power. Oops.yeah i was surprised when i had to put together the ecu harness for my turbo altima. i had to make sure that i differentiated between chassis grounds and ecu grounds. started first try too. clipping the wire and running it directly off of the relay doesnt work, btw. it needs the complete circuit to turn the pump on. i thought it might be that way, but i tried it just to make sure.

[WIKID S4TEEN]

or something is up with your ignition switch. .

This...
Test the output of this ignition switch.
Tell us what it reads with the key is on and off.

[KiLLeR2001]

I drew up a quick diagram of what you need to do.

http://i.imgur.com/D9QH8.gif

From battery to the fuel pump should always read around 12v. If when you turn the car on, and voltage drops to 11v then you either have resistance in the fuel pump wiring itself OR there is a loose connection with the fuel pump wiring. If this is the case I would pull out the fuel pump and inspect the wiring there, it is not uncommon for there to be bad crimped connections. Worst case scenario something is wrong with the pump.

[AsleepAltima]

i think we might have lost sight of the problem. lol
the problem is more than likely subpar 1991 wiring with a 1991 fuel pump relay. theres no problem AT ALL if i wasnt running a car that needed more fuel pressure from boost. the car starts and runs just fine. shuts off just as well. i just need to provide more juice to the fuel pump. its that or i run all new wiring from the original relay all the way to the pump. im not doing that. lol
i left the wiring intact because i wanted the ecu to continue to control pressure - such as shutting the pump off when the engine isnt running. in essence, i want this to be turn key as it originally was. all i need to know now is, why is it continuing to run when the (added) fuel pump relay isnt receiving the input voltage to energize it? i honestly cant see where the ignition switch comes into play. the voltage coming out of the car side of the original fuel pump harness is enough to energize the second relay. as a result, the relay is providing the much needed 12+ volts to fully run the fuel pump as needed. the problem is the engine continuing to run when the key is off when it shouldnt be providing power anymore. thats it. /rant

[AsleepAltima]

I drew up a quick diagram of what you need to do.

http://i.imgur.com/D9QH8.gif

From battery to the fuel pump should always read around 12v. If when you turn the car on, and voltage drops to 11v then you either have resistance in the fuel pump wiring itself OR there is a loose connection with the fuel pump wiring. If this is the case I would pull out the fuel pump and inspect the wiring there, it is not uncommon for there to be bad crimped connections. Worst case scenario something is wrong with the pump.
i will use this diagram and see if it works. just so you know though, the same thing happened with both walbros that i tried and the wiring was intact when i checked it, a few days ago. i think honestly, that the problem is a weak nissan fuel pump relay. it still doesnt explain though why the car continues to run with the key off :/

[Broadfield]

Call me right now... 309-261-4827

Toby

[KiLLeR2001]

Oh I thought you were running independent wiring to your fuel pump...

I would replace the factory wiring with fresh wire, but first check your connections on the fuel pump itself. I replaced my pump not too long ago and the connections were very weak.

[KiLLeR2001]

i think we might have lost sight of the problem. lol
the problem is more than likely subpar 1991 wiring with a 1991 fuel pump relay. theres no problem AT ALL if i wasnt running a car that needed more fuel pressure from boost. the car starts and runs just fine. shuts off just as well. i just need to provide more juice to the fuel pump. its that or i run all new wiring from the original relay all the way to the pump. im not doing that. lol
i left the wiring intact because i wanted the ecu to continue to control pressure - such as shutting the pump off when the engine isnt running. in essence, i want this to be turn key as it originally was. all i need to know now is, why is it continuing to run when the (added) fuel pump relay isnt receiving the input voltage to energize it? i honestly cant see where the ignition switch comes into play. the voltage coming out of the car side of the original fuel pump harness is enough to energize the second relay. as a result, the relay is providing the much needed 12+ volts to fully run the fuel pump as needed. the problem is the engine continuing to run when the key is off when it shouldnt be providing power anymore. thats it. /rant

This is exactly why it could be your ignition switch. After you shut your car off, and the engine is still running, you need to probe the IGN ON to see if there is 12v. If so, then you need a new ignition switch. As long as the ECU thinks the car is ON, its going to keep the fuel pump on, and the engine spinning.

Call Toby, he will be able to solve it guarenteed!

[AsleepAltima]

This is exactly why it could be your ignition switch. After you shut your car off, and the engine is still running, you need to probe the IGN ON to see if there is 12v. If so, then you need a new ignition switch. As long as the ECU thinks the car is ON, its going to keep the fuel pump on, and the engine spinning.

Call Toby, he will be able to solve it guarenteed!
ill call him and i think you just answered what is going on - the relay is sending power back thru the fuel pump wire, through the relay and to the ignition switch. there are no diodes anywhere in the system i think so its keeping everything energized. when i switch the toggle and break the circuit, the relays click closed and dont have input voltage to come back on. ive seen this happen on cars that have improperly wired electric fans and when the car is shut off, the spinning fan is providing voltage until it stops.

[KiLLeR2001]

Ding ding ding. We have a winner!!!

:)

[WIKID S4TEEN]

It's your switch bro!
Turn off the key. Take your Fluke. Measure output of switch.

[AsleepAltima]

toby is the man! it wasnt the relay, it was a simple matter of needing to cut one wire and interrupt it with the relay. i walked him thru what i had and he walked me thru to what it should be. voila! engine runs now as needed. :D

THANKS TOBY!

[KiLLeR2001]

Toby is a goddamn monster. LOL.

[Broadfield]

THANKS TOBY!

Anytime!!!

[godsmack]

i was trying to tell you that from the start there bud. but i'm glad you got it all figured out.

[AsleepAltima]

i was trying to tell you that from the start there bud. but i'm glad you got it all figured out.
the problem was though, that i was using the 12v switched side as the trigger. the funny thing though, that wire didnt need to be used at all. so, with toby's suggestion, i rewired that to itself and took it out of the relay equation. THEN, we took the 12 volt wire that supplies power to the pump, used the car side as the trigger and the pump side as the power. that was the missing piece of the puzzle. the relay was not wired incorrectly, it was me using the wrong source of power for the trigger. i think im going to do a quick write-up for people with wire colors and pins so anyone can do this - like i did with the lsx coils on another site.

[godrifttoday]

Yayayyy!!!

[WIKID S4TEEN]

Good to hear you got it going. If you're gonna do a write-up, I would suggest, using the proper terms when dealing with a relay (C, N/O, N/C, etc.).

[AsleepAltima]

Good to hear you got it going. If you're gonna do a write-up, I would suggest, using the proper terms when dealing with a relay (C, N/O, N/C, etc.).
thanks and will do but im going to dumb it way the hell down and use numbers and wire colors. that usually works better for most people. :bigok:

[Broadfield]

Good to hear you got it going. If you're gonna do a write-up, I would suggest, using the proper terms when dealing with a relay (C, N/O, N/C, etc.).

I have wired over 4,000 relays in my 20 year profession and have never used those terms... we use the standard 85, 86, 87, 87a and 30 when describing the circuit.

[AsleepAltima]

I have wired over 4,000 relays in my 20 year profession and have never used those terms... we use the standard 85, 86, 87, 87a and 30 when describing the circuit.
that to me makes the most sense. ive been working on helicopters since 94 and believe it or not, everything we use for reference during maintenance is dumbed down to 3rd grade reading level because we need to be sure that the mechanic can understand what needs to be done. lol. to me, chassis specific wire colors and relay terminal numbers work the best. when i wrote up the lsx coil conversion, i made it stupid easy so that anyone can do it fearlessly.