Being my first forum question, I'd just like to start by saying HEY to everyone out there in blazer land, and thanks for any reply or suggestions received. I have a '95 T-10 blazer with a really odd problem. The problem is that when I start her, everything appears normal until I turn the air conditioning on. As soon as I turn the **** to engage the A/C, the ABS and the PARKING BRAKE warning lights in the instrument cluster illuminate. The A/C does not come on and there is no blower action. None of the other functions related to this **** work. Also, the power windows do not work (and boy is it hot in there) and the cruise control does not work. All other electrical functions work including the dash lights, lighter, radio, dome lights, door locks, turn signals, emergency flashers, head lights, brake lights, wipers, back hatch release, digital compass, outside temperature display, and the horn. Everything is the same if I turn just the ACC power on. The ABS and the PARKING BRAKE warning lights will also come on if I attempt to roll down the window, but only on the driver's side. The other three windows will not roll down, but do not have the effect of turning the ABS and the PARKING BRAKE warning lights on. I have taken her to a couple of shops and the local CHEVY dealer, but have come up short on a solution. Once again, thanks for any replies!

 

Welcome to the forum.
Have you had any work done recently? Engine or electrical work?
It sounds like a bad ground. There are many grounds, unfortunatly I have recently lost (temporarily) my website with wiring diagrams.
There are many here that can help though.

 

One thing I'd REALLY go over well is there's a bundle of cables that JUST so happen to go to the ECU (I'm pretty sure that's what it is) it sits over on the passenger side right under the hood (big box with couple BIG *** connectors goin' to it) and coincidently the blower motor is RIGHT there behind it in the firewall there. there's some big bundles of wires there... I'd figure out how to get them unwrapped and inspect them GOOD! and just use some of that wire loom stuff to put 'em all back together when you're done... might find something like some wires with the insulator burnt off or something... someone could have had a component or something go and heat up some of those wires and maybe melt the insulators causin' some to be shorted together (I've seen it before on my first car a VOLVO... EWWWWW.. HEY my dad bought and gave it to me...lol)... and yes Chevy Lover is correct it could be a bad ground somewhere and causin' something to try to "sink" to ground through another component... been there done that in electronic pc boards....


Here's the blower circuit w/ac and the 4 instrument panel circuits (there's a $HITLOAD more wiring diagrams for our year) so if you need anymore just let me know!

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This is my wife's truck and I do not drive it frequently. I havent had any electrical work done for quite some time, at least 4 months. At which time it was just a routine check of the A/C, which was fine, according to the shop. I had to pull the dash shortly after the A/C checkup to replace a leaking heater core. After the install, everything worked like it should until recently. I have deceided to let the chevy dealer have another crack at it. Driving to the chevy dealer, with no electrical device turned on, I noticed that when the truck was at an idle, everything was ok. However, during normal operation, when the (AT) transmission would get just to the point of shifting, the ABS and Brake warning lights would come on. After shifting to 2nd, and leveling out, the lights would go out until the transmision reached the point of shifting into drive, and also OD. Once OD was achieved, the lights would go out once again. The same sequence would occur when going through the down shifting process of stopping. And I also noticed, that while these lights were on, the transmission would be unusually loud, but only when the warning lights were on. While the lights were off, transmission in OD, the transmission cruised along just fine. I've never seen or heard of anything like this before.