1994 Astro dead-electrical?? Need help please!!

[bretcopsey]

It started acting up a few days before it just flat out died. Symptoms were stalling for what initially seemed to be no reason. After a day or so I noticed the engine stumbling coincided with switching on the headlights, or if not that then the brights. Or when parked, still running and opening a door-triggering the dome lights.

Ultimately the other day it had been running/driving fine for several hours. I made a quick stop and when attempting to restart, it refused. I noticed not hearing the fuel pump, so even though I just replaced it two months ago, I dropped the tank and replaced it again-still the same. I cleaned up the fuel pump harness ground at the frame, then I started looking under the hood and found the connector for the fuel pump relay had melted. Spliced in a new connector and replaced the relay-still not getting power to the fuel pump. I can get the new pump to run by using the test connector pigtail to +12v.

Other symptoms currently: Fuel pump will only come on when jumped-not with key; headlights will not come on and neither will dome light; radio has no power to check time when key off; radio keeps resetting to 12:00 each time key is turned to on, as if battery has been disconnected then reconnected. I have checked the fuses in the block plus a couple others I found under the dash and none are bad. Fuseable link? Bad ground? Bad ECM? Anyone have any suggestions?

[MonzaRacer]

Start at beginning, at battery. Charge it up, make sure you have clean connection from cable to terminal as batteries get older they can leak and cables will corrode where terminal is crimped on. Also look for heavy 8 to 10 gauge cable coming from positive terminal it may go to a main power block or to the starter or alternator look for the plastic "bullets" that mark fuse links, best check for a blown link is given a pull, if wire is burnt it will pull easy and the insulation will stretch. I dont have source for wiring Diagrams right now so asking in electrical section if you can get power distribution diagram from someone might help looking.

[bretcopsey]

Found this, not sure what I'm looking at though....I hate electrical!

[absintheisfun]

If the fuel pump relay was melted it is more than likely not a ground issue, but a high resistance issue somewhere in the wiring. I would start chasing the wiring from your fuel pump all the way to the 12v source. I would bet that your issue is a wire or switch with high corrosion somewhere. Because of their high power demand, usually the Fuel pump is on a dedicated circuit which makes me think that your lighting issue is a seperate problem.

If you have a multimeter start ohming the wiring...if not, use a test light and hit one wire at a time and see if the light is dimmer on one wire than another.

Best of luck to you-chasing down bad wiring is a nightmare!

I've highlighted the parts in the schematic above that you should check first:

[David Pozzi]

Check your cable connections at the battery. Remove them & verify they are clean.

[bretcopsey]

Problem solved. There was another melted harness connector located behind the battery.