Diagram or schematic that shows where each wire goes through the firewall from engine into the backup the fuse box under dash needed?

Tiny
VANMANG20
  • MEMBER
  • 1998 CHEVROLET VAN
  • 5.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 25,648 MILES
My fuse box underneath the dash is only partly working. It seems there is no power to the fuses in the middle of box. The outside fuses work fine. The ECMB fuse works but no power to ECM fuse. Under the hood above the battery is a cluster of cut wires and wires that are hot but not going anywhere. My van won't start at all. I'm pretty sure the problem is the fuses in the engine compartment. My question is, is there a diagram or schematic that shows where each wire goes through the firewall from engine into the backup the fuse box under dash?
Thursday, June 15th, 2023 AT 10:24 AM

10 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
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Sure, here is a guide to help you check the power feed wires and the wiring diagrams to help you see how the system works and which wires to test.

https://www.2carpros.com/articles/how-to-check-wiring

I would test the ignition switch first. Check out the images (below). Please let us know what happens.
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Friday, June 16th, 2023 AT 8:02 AM
Tiny
VANMANG20
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Hi,

I tested the ignition switch, and it seems to be working fine. I'm hoping I don't have to drop the gas tank. My fuel pump primes the lines up to the TBI but stops before it hits the injectors. I replaced injectors. The van runs with constant prime. But it won't start on its own as it's not getting the gas. After the pump primes and shuts off about 1 min to minute and a 1/2 later, I hear some kind of dripping like water dripping after u turn the shower off inside the tank. I'm baffled. It seems all problems are pointing to fuel pump. I'd be appreciative beyond if you can give me an idea of what to do. Also, is there a fuse connected to injector wires somewhere that could be blown? A friend said look for it and make sure the fuse is good. I haven't found it. One more thing, the pump runs too long to prime and when I turn the key off, I lose all pressure and when I turn the key back to on position the pump runs for minutes until it builds pressure again.
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Monday, June 19th, 2023 AT 9:22 AM
Tiny
KEN L
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I have seen the fuel line inside the fuel tank fail which will cause the problem you are describing. Here is how to remove the tank so you can check out the pump. Check out the images (below). Please let us know what happens.
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Tuesday, June 20th, 2023 AT 9:50 AM
Tiny
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Thanks! Going to try that next.
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Tuesday, June 20th, 2023 AT 4:11 PM
Tiny
KEN L
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Sweet! Please let me know.
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Wednesday, June 21st, 2023 AT 9:50 AM
Tiny
VANMANG20
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So pretty sure this was the problem.
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Thursday, June 22nd, 2023 AT 12:31 PM
Tiny
VANMANG20
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Sending unit and pump/filter fell apart as I was pulling it out. Now that it's out, any ideas on how to clean the tank out? The van sat for years. It's pretty nasty in there.
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Thursday, June 22nd, 2023 AT 12:34 PM
Tiny
KEN L
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Good find, yep cleaning the tank can be a challenge. I would use new gas and clean shop towels and mop up the mess while rolling the tank around to try and get as much out as possible. If it cannot be completed successfully a new tank is in order.
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Friday, June 23rd, 2023 AT 10:21 AM
Tiny
VANMANG20
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Cleaned the Tank out like you said. Worked like a charm. Obviously the fuel pump is trash as it disintegrated as I pulled it out of the tank, but the sending unit looks okay. Any thoughts on keeping the sending unit and buy new pump?
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Sunday, June 25th, 2023 AT 7:50 AM
Tiny
KEN L
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I would send a new sending unit; they can go bad internally with rust and since you are there might as well. Let me know how it goes.
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Monday, June 26th, 2023 AT 11:43 AM

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