Electrical problem
1999 Chevy Astro 6 cyl All Wheel Drive Automatic 92000 miles
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I had a basic tune up to my van last week. New wires, plugs, dist cap, fuel filter, serpentine belt, new drivers side window motor and condenser for a/c fan because it was working intermently.

Today van suddenly would not start this morning so had battery replace and started fine.

This evening van suddenly had windows, fan, radio all stop working at same time and the abs light came on. Van still seems to run okay so I dont think it is the alternator? I checked fuses and did not see any of them blown? Any ideas what would cause a sudden failure like this? Seems like maybe a short in relation to one of the repairs that were made?

Several things to check first:

Check battery voltage with key off.
Check battery voltage with key on, engine off.
Check batery voltage with engine running.

Battery voltage should be 12.4 on the first, slightly lower on the second and around 13.3-13.8 on the third. The answer to this question will determine which road we take next. Post back with the results and we'll go from there.

i have the exact same thing happen to my 99 astro just today out of nowhere. checked voltage at the battery, all voltages are like you said.. normal. this vehicle has had intermittent electrical problems from day one. we bought it new in 99. every so often the fuse for the power locks blows, i just replace it and it lasts for a couple weeks usually. now this problem, same as original poster exactly. all fuses are good. windows, fan, radio, wipers, none of that stuff works now. i wish i could get to the bottom of this, GM really screwed up this design imo. something very wrong.

thanks so much, hope to hear from you soon as i can't close my windows!

tony

Hi Colts and Leadfoot, I am having the same problem on my 1996 Astro. Did you guys ever find a solution?

After three weeks of nights and weekends tearing apart my wifes 99 astro I finally found the problem. As I mentioned, the van kept blowing the 40 amp main fuse that controls the windows, fan, wipers, and radio..(the ignition 'b' main fuse). After replacing the ignition switch and coincidentally having the alternator go out during the process, putting it all back together several times and still having the problem.. my wife says, "it seems to happen whenever I open the window(mostly)". so having tried everything else, and I have wiring schematics that I got from my mechanic buddy, I decided to tear into the door and see if anything is out of whack in there. I didn't do this at first because I figured if there was a problem with the window wiring, it would blow the individual window fuse located under the dash, which it never did. Turns out sure enough, the wires in the door were getting mangled by the operation of the window arm that moves the window up and down. The harness inside the door runs right along side the moving parts in there and the gear arm cut right into three wires in the harness. But still why wasn't it blowing the window fuse? Turns out that the window fuse is a 30 amp breaker type fuse and was stuck closed and would not trip!! That one threw me for a loop for 3 weeks! That's why it was blowing the main fuse.
Sounds like that might be colts problem too, as I notice he had a new window motor put in.
I searched through the whole wiring harness under the dash and the wiring block that penetrates the firewall, over and over before finding this, and that was extremely difficult, you can't even see it let alone get to it to work on it. At least it was worth it cause I found a couple other small wiring problems while I was at it, now everything is back to normal. Actually better than normal, when we first bought the vehicle, it had electric problems since day one that an entire shop full of mechanics could not figure out.. It kept randomly blowing the electric lock fuse, all these years I figured if a shop full of mechanics couldn't fix it, I wouldn't be able to. But in the process of working on those other problems, I found a taped up factory splice that the wires were poking thru the tape and arcing to some metal part above the steering column so I fixed it as well. Now it's all good.

Sorry this post is so long, but hopefully it will save some folks with similar problems a lot of grief. I couldn't ignore this problem, cause we need that vehicle as we both work full time and have a six year old daughter. I had serious doubts that any shop mechanic would find the problem or if they did it would cost a small fortune in labor time to find it, so I made up my mind to tear into it myself. I am a union electrician, but I knew before hand how tough electrical problems in a car can be, mainly because access is so limited without tearing the whole dash out.. which I was almost ready to do.

Good luck, and if you have time, let me know if this helped at all.

Tony

Hi Tony,

You're a genius! That was it exactly. One of the wires for the power window was rubbing against the window regulator and had worn through a bit, causing it to blow the ignition 'b' main fuse. Replaced the fuse and repaired and moved the wire so it will not get damaged again, and it works like new, as do the wipers, radio and heater fan.

Thanks so much for the insight man, that problem was driving me nuts. Hope I can return the favor one day!

Rich

I have a problem that leadfoot64 (Tony) mentioned in his second post.

'98 Chevy Astro AWD

I have power locks and dutch doors and an aftermarket remote keyless entry from JCWhitney

So here's the issue. My driver's side door lock causes my power lock / radio / cigarette lighter fuse to blow.

The actuator isn't moving very much, but it is moving. It seems like the lock itself is jammed or something, but I'm not really sure. When I hit the UNLOCK button is when the fuse blows. It will lock with no issues, but the fuse blows every time I unlock the doors.

I'm not sure if it's the actuator (like I said, it still moves; would that blow the fuse if the actuator was on its way? They're too expensive to just try it).

Is it possible that the lock mechanism is just jamming up and that's what's causing the fuse to blow? It seems like I can only unlock my doors once before the fuse blows...

The biggest problem is that the rear hatch is purely electrical, and so my rear doors can't be opened unless I have a fuse to waste. It's a pain in the butt, and I haven't really had the time to go tearing EVERYTHING apart. If anyone can help out a college student with limited time and cash for this problem, it'd be greatly appreciated.