Fuel Pump Not Priming

JBuild

Member
Definitely don't have a ground at pin 85, which I think should be the top left. Mine has 6v so that's an issue.

From what I can tell there's some circuitry in the fuse box as that pin doesn't directly feed a wiring harness wire so I can't cheat the ground.

Does anyone have a spare fuse box they want to sell?
 

ccannx

Goblin Guru
I had the same issue you can probably ohm out the pin with a meter and find some common pins to it with a wire to tap on and ground to the frame.
 

JBuild

Member
Figured it out, turns out one of the traces on the fuse box circuit burnt up. Ran a jumper on the board and it fixed the issue. Not sure I trust this for a long term solution so I found a reasonably priced used one.

When standing at the back of the car the top left pin should be a constant ground even with the fuel pump disconnected.

For anyone that needs to be disassemble the fuse box be careful not to break the latches that go over the bottom part of the fusebox mount. While I was holding one of these it cracked off but I will say mine seemed to be a little more brittle and sun faded than others.

Fuse box separation procedure, make sure the box is at least room temperature but the warmer the better:
Remove all the fuses and relays
Remove the bolts and the retainer washers from the backside
Remove the positive terminal by pressing on the tab that holds the lug in place
With a small screwdriver gently slide it between the two halves near the locking tabs, this will space out the larger outer half. I worked around mine a few times
On one of the corners mine already had some play between the halves so I started there and just slowly worked my way around.
Below is the burnt trace, I ran a jumper from R12-86 6 to R1-86 6
10603
 

Brett

Well-Known Member
What I did to fix this was take some copper wire, wrapped it around the post, solder it, and replace the circuit with the wire.

Replacement fuse boxes are available but they are expensive. If the wire wrap works then go with it.

This is a technique that was used extensively in telecom and on mainframes among other systems.
 

dastrups

Well-Known Member
What I did to fix this was take some copper wire, wrapped it around the post, solder it, and replace the circuit with the wire.

Replacement fuse boxes are available but they are expensive. If the wire wrap works then go with it.

This is a technique that was used extensively in telecom and on mainframes among other systems.
Do you mean from this port to this port? And then solder? I am clueless when it comes to these things.
 

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Brett

Well-Known Member
Do you mean from this port to this port? And then solder? I am clueless when it comes to these things.
Its hard to tell but it looks like you have it correct. The key is to follow the burned up circuit trace and replace with with a wire (leave the insulation on the wire). Solder the wire to the pins that are connected to the burned up circuit trace.

Be sure to inspect the circuit board for any other burned up traces. You are this far into it, you might as well look for others. Mine was burned up in a small area, about a mm long.
 
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