for some reason, when i pull hazard switch, my fuel pump goes on (flashes on off), - carbed v8 Options

[jimkelly]

my fuel pump also goes on when hazard switch is not pulled but key is turned.

the circuits have got to be connected somehow???

could this be a faulty relay board?

or could it be that I put a wire on the wrong spot on the fuse box?

my engine is a carbed sbc v8.

i'm using the 2 harness wires to power my fuel pump.

thanks
jim

[Dave_Darling]

Since it isn't stock, the first thing to do is check out the fuel pump wiring. Where is the pump actually getting power from? Then chase the circuit from there.

--DD

[ConeDodger]

Ha! The old Bumblebee Racer used that as a theft deterrent. If you didn't pull the fog light pull, you could crank it as long as the battery lasted and it wouldn't start.

I would consider that possibility if the car is new to you... Might have been rewired to prevent theft.

[rhodyguy]

stock pump harness with new pump end connections?

[jimkelly]

yes - fuel pump connected to stock harness, like it had been before.

and it gets power from key. but also gets power from hazard switch when pulled.

pic shows + disconnected.

the reason I ask is because the + black/red wire goes to relay board (pin 13, I think). but I assume the hazard switch sends power thru the relay board too?

[jimkelly]

seems my 14 pin plug has power at 12 and 14 pins with key off.

with ignition key turned, 12, 14, and 8 and 3, have power.

I was expecting one pin to flash with the hazards but none did. but I guess without plug connected to relay panel, that was an ill conceived expectation.

pins 11 and 6 are empty.

its got to be how I wired my fuse box???

[r_towle]

go back to the fuse panel and find the black/red stripe wire.

Sounds like its fed off the relay...which may be up on top of the fuse panel...the one for the flashers.

rich

[jimkelly]

there is a black/red wire at the fuse box but it does not seem to lead to the harness. it comes out of the silver relay and goes to the 20 amp fuse with a red wire, but only red wires are on the other side of the fuse??

to me, it could simply be a coincidence that this wire at the fuse panel happens to be black/red?

if the ecu turns the fuel pump on, then maybe there is no wire to trace, other than the one from pump to relay board?

note: my fuse box did get a little burnt from the recent short/fire, but I think it is ok?

[Dave_Darling]

Do you even have an ECU? With a carb'ed V8, I sincerely doubt it.

Trace the wires. Seriously--trace them. Start at the pump, look at the wire color, trace that back through the wiring harness to wherever it goes. If it goes to the relay board, look at a relay board diagram to see if it connects to anything else in there. (Some do, some don't.)

Keep tracing the wire until you get to one or another of the switches.

Someone did the conversion to V8. That means the stock fuel injection doesn't work. So the pump control circuitry had to be changed. You need to figure out how it was changed, so you can start troubleshooting.

--DD

[jimkelly]

nope, no ecu.

this car ran before, wired like it is.

I am thinking to simply wire the fuel pump to a switched positive.

though I think my wipers are not working, I need to see if I have a second issue.

did this to trick the relay board.
http://www.914world.com/bbs2/index.php?showtopic=25954

thanks
jim

[HalfMoon]

I also have a dark one (v-8 converted) and experienced a very similar problem. It was one of the relays behind the board.

nope, no ecu.

this car ran before, wired like it is.

I am thinking to simply wire the fuel pump to a switched positive.

though I think my wipers are not working, I need to see if I have a second issue.

did this to trick the relay board.
http://www.914world.com/bbs2/index.php?showtopic=25954

thanks
jim

[Spoke]

The use of the relay on the relay board to turn the FP on is a good idea. The FP may draw a lot of current which is why you wouldn't want to run this current through the key via a switched positive.

Like Dave said, trace the wiring to/from the fuel pump.

Try this test: turn on the flashers on (which I think turns the pump on), then disconnect the coiled red wire from the relay board. The FP may stay running. If it does, then something besides the relay is powering the FP.

[jimkelly]

I need to figure out which of my 4 relays are for what.

since I don't have a heater fan or fog lights, 2 relays are not needed.

damn electrical (IMG:style_emoticons/default/headbang.gif)

[jimkelly]

nope - pump did not work with coiled wire (which acts as ground) disconnected from relay board.

though if I leave this wire connected, but run positive wire from fuel pump directly to battery positive, it runs fine.

so the ground thru the relay board is not the problem, the fuel pump harness positive seems to be the problem.

though I did try to get positive from my fuel pump from this spade (pic below) and ground to body, and same problem.

seems to me that these 4 spades on the relay board for fuel injection harness has an issue?

(IMG:http://www.914world.com/bbs2/uploads/post-7407-1320344447.jpg)

jim

---------------

The use of the relay on the relay board to turn the FP on is a good idea. The FP may draw a lot of current which is why you wouldn't want to run this current through the key via a switched positive.

Like Dave said, trace the wiring to/from the fuel pump.

Try this test: turn on the flashers on (which I think turns the pump on), then disconnect the coiled red wire from the relay board. The FP may stay running. If it does, then something besides the relay is powering the FP.

[jimkelly]

also, do I need the volt regulator (I thought my GM alternator has a regulator built in it?) - and the second relay - see arrows?

I do have a relay board on the shelf, don't know if it is good but assume so.

also, when I said switch positive, I meant run the neg wire from the FP to ground and run a positive wire directly to the battery positive with a switch on the line.

but this does not solve the mystery problem which may have other effects yet to be discovered. I do know my wipers are not working.

[Spoke]

I need to figure out which of my 4 relays are for what.

since I don't have a heater fan or fog lights, 2 relays are not needed.

damn electrical (IMG:style_emoticons/default/headbang.gif)

Relays starting from the rear of the car:
1) Heater fan relay that goes on top of the motor: You don't need this one.
2) Fuel pump relay: you need this.
3) Power supply relay: you need this. It provides power to the fuel pump relay coil.
4) Rear window defogger relay: If you don't have the rear defogger, you don't need this.

The fog light relay is in the front of the car.

[Rand]

.

[Spoke]

nope - pump did not work with coiled wire (which acts as ground) disconnected from relay board.

Spoke: This is expected with the key on. Please explain what else was happening here. Key on/off? Flasher on/off?

though if I leave this wire connected, but run positive wire from fuel pump directly to battery positive, it runs fine.

Spoke: What you did here was power the FP from the battery. FP has 2 contacts. One is ground, the other powered to 12V through the relay board relay. You bypassed the relay and powered directly from the battery.

so the ground thru the relay board is not the problem, the fuel pump harness positive seems to be the problem.

Spoke: Try this, key off, flasher on. I think you said the FP runs, correct? Remove the 2nd relay looking from the rear of the car. Counting relay sockets here. Does the FP still run? Trying to see if you have a short in wiring to the FP. Also is the FP in the front of the car?

though I did try to get positive from my fuel pump from this spade (pic below) and ground to body, and same problem.

seems to me that these 4 spades on the relay board for fuel injection harness has an issue?

Spoke: Not necessarily a problem. You only need the front left spade to be ground like you had. This turns on the FP relay. Normally the FI would ground this to run the FP.

[mepstein]

Ha! The old Bumblebee Racer used that as a theft deterrent. If you didn't pull the fog light pull, you could crank it as long as the battery lasted and it wouldn't start.

I would consider that possibility if the car is new to you... Might have been rewired to prevent theft.

I had that done on my car

[jimkelly]

jim: nope - pump did not work with coiled wire (which acts as ground) disconnected from relay board.

Spoke: This is expected with the key on. Please explain what else was happening here. Key on/off? Flasher on/off?

JIM: WITH KEY OFF AND HAZARDS PULLED, LIGHTS BLINK AS THEY SHOULD AND FUEL PUMP GOES ON AND OFF WITH LIGHTS. WITH HAZARDS NOT PULLED, BUT IGN KEY ON, FUEL PUMP RUNS STEADY. I HESITATE TO SEE WHAT HAPPENS WITH KEY TURNED AND HAZARD SWITCH PULLED.

Spoke: What you did here was power the FP from the battery. FP has 2 contacts. One is ground, the other powered to 12V through the relay board relay. You bypassed the relay and powered directly from the battery.

JIM: OH.

so the ground thru the relay board is not the problem, the fuel pump harness positive seems to be the problem.

Spoke: Try this, key off, flasher on. I think you said the FP runs, correct? Remove the 2nd relay looking from the rear of the car. Counting relay sockets here. Does the FP still run? Trying to see if you have a short in wiring to the FP. Also is the FP in the front of the car?

JIM: DID THIS AND FUEL PUMP DID NOT RUN.

>> 2 FRESH PICS <<