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I just picked up a project 1986 corvette and the fuel pump is not kicking on. I changed the fuel pump relay and nothing. Now I found that I am not getting power to the orange wire on the relay which is supposed to get power at all times. I read that a fudable link behind the battery might be blown but they all look normal to me, nothing seems to be burnt up. Any ideas?
This diagram is a (corrected) wiring diagram for the fuel pump voltage supply circuitry:
You can force the fuel pump to come on by removing the oil pressure switch connector and jumpering between the contacts of the connector.
If you don't have voltage on the orange wire then fusible link H could be blown. It's connected to the ECM power connector which is attached to the battery cable on the positive battery terminal. It is hidden under the brake booster:
Ok, so I just tested the fusible link and checked continuity from the connector in the picture all the way to the orange wire and that is all good. I believe that should mean that I'm not getting power to that connector from the main red battery wire. I'm fairly new to all of this stuff so I appreciate the help and I might sound like an idiot from time to time..lol.
I've been messing around with the wiring and I think there is a break in the power line to the fuel pump relay, if I move the positive battery cable around a bit I get continuity between the positive terminal cable and the relay, but a little jiggle the wrong way and I lose it.
I've been messing around with the wiring and I think there is a break in the power line to the fuel pump relay, if I move the positive battery cable around a bit I get continuity between the positive terminal cable and the relay, but a little jiggle the wrong way and I lose it.
[I]I hope so, I picked up a new positive cable repair splice to just replace the entire end of the positive cable, is there any issues with doing that, I've never done it before. the 2 aux wires seem to be slightly smaller than the aux wires on there now, I just don't want to burn them up. Here is the link to he part I got http://m.oreillyauto.com/h5/r/oap/si...2636&ppt=C0005
Well I took your advice and cleaned the wire and terminal up and now I get power to the fuse thankfully. But still no power to the fuel pump. When I put my test light in the fuel pump fuse it will only work if the 3 prong connector in the back at the fuel pump is disconnected. Any ideas? I e also tried to put my test light in each of the 3 prongs with the fuse in and I'm getting nothing. I do hear a quick 3 "bah bah bah" noise when in turn to ignition, no clue what that is but it sounds like it's coming from the back end. And yes, I know it will only kick on for 2 seconds in the on ignition position.
Run a wire from battery positive terminal to terminal "G" of the ALCL connector. That should give you power all the way to fuel pump.
Should help you test and see if pump runs.
So to drag this post up again. I had finally gotten my vette to run, and then no power to the fuel pump again..lol. I bought a whole new sending unit and fuel pump relay. It was running great without any issues and now I changed out a bunch of fuses in the fuse panel and I don't et power to the fuel pump. When I put the test light in the fuse socket it lights up for the 2 seconds. When I put the light on the connector at the fuel pump I get nothing. I'm not great at electronics but looking at the diagram above, it doesn't look like there is anything between the fuse and the connector, does that mean that there is s bad wire from the fuse box to the pump?
The engine has to be rotating (cranking or running) for the ECM to turn on the fuel pump relay. Many people just assume there should be power on the fuel pump (and the FP fuse) when the ignition is turned on. Not so.
I only tested the one side of the fuse, I'll have to check the other side. I've tried different fuses and even a piece of wire just to see if I could get power to the back and nothing.
I only tested the one side of the fuse, I'll have to check the other side. I've tried different fuses and even a piece of wire just to see if I could get power to the back and nothing.
Well I think I found the problem, the bottom half of a fuse holder is considerably messed up, I attached a pic but it's hard to tell. I'm assuming the only way to fix this is either replacing the whole fuse box which I really don't want to do or put an inline fuse on the fuel pump wires and skipping the fuse panel all together. Question is how the hell do I get the fuse panel out or gain access to the wire I need to. Or any other ideas would be much appreciated, I guess I bought quite the project
05-22-2016, 10:10 PM
No power Fuel pump
