Please help! 93 Chevy Astro


#1

I have 1993 chevrolet astro van. was driving the van and hit the passenger power window and lost all power inside, Gauges,wipers radio heat… Headlights and dome lights still work… No start… Replaced alternator and fuseable link at starter, still nothing… Can unplug plug from alternator and run 12 volts directly into plug (NOT ALTERNATOR)and everything works fine until I remove the 12 volts from the plug then all dies…Have had several people try to help but have had no Luck Please Help


#2

Why are you not concentrating on why operating the passenger window causes these symptons to appear?

I don’t have a clear picture of what you are doing in regards to the “alternator plug”

Was there a sympton that led you to replace the alternator and the fuseable link you mention?


#3

I removed the window switch. when I unplug the alternator, I hold the plug in my hand and with the other hand I put 12 volts into the plug and everything comes on and the van will even start but when I pull the 12 volt off of the plug, everything dies. The alternator was making squealing noise, had it tested at AZ and was bad, The fuseable link was just a guess… Have had same symptoms from other vehicle and it was fuseable link


#4

First thing that comes to mind is that you say you had these same symptons on another car,what are the odds?..this is a wierd one.

Are you putting 12V to the large wire that is normally the alternators output? or are you putting 12V to one of the smaller gague wires that are normally for field excitment or the battery light? What gave you the idea to do this? Previous same symptons on another car?

I still think you need to make a link between operating the power window and all these symptons.

Are you troubleshooting off a schematic? if not you need to be,follow the schematic and find out why things are “activating” when you input the voltage in the way you are.

Powering up the electrical system backwards (this is what it sounds like to me based on your information provided)is not a normal or safe method.

Along with the schematic check out and the window circuit questions a good visual inspection (looking for harness concerns,connection concerns) is required.


#5

Let me start over. This van belongs to a friend of mine who asked me to help him change the alternator. I am no electrician and am used to older stuff. I didnt find out about the window deal until after the alternator swap. As for powering the electrical system backwards that was the idea of the neighbor to get the van running long enough to get it home. I do not have a scematic and the guy cant afford to take the van to a shop. I dont know what to tell the guy (BTW the wiring at the window switch is all cut and jumbled together) So i guess thats a good place to start. Is there any good places to get scematics on the internet.


#6

I don’t have a solutions but here’s a thought…

Try the horn and brake lights too. If they all work, then it narrows it down to the ignition side (I think that’s what you meant when you were talking about the alternator plug).

I had an old car that might have had a similar problem. The socket travelling from the under the hood through the firewall was hardened, cracked, and corroded badly. It was an old car so I ended up ripping the plug out and hard wired everything.


#7

Problem was fuseable link behind the battery. Thanks for The help