power windows and a/c elec. issue

cnomad172 · 06-29-2009, 12:23 PM

hey guys, i have a 97 blazer lt with the 4.3l. when i bought the thing about a year ago, it had an occasional issue that when you started it, the a/c and windows wouldn't work. well i sniffed around and found that if i tapped the far left realy of the three on the firewall.. the compressor would kick on and everything was ok. this issue started occurring more and more often. then i had to hit the realy harder and harder. now, when i can get the a/c to come on.. as soon as i hit the power windows everything quits again. i traced the larger purple wire from this relay to the a/c blower. when i unhook the blower and the compressor and try the windows, it just makes the dash start it's whole startup cycle again. this also happened when the a/c would not kick on to beghin with. i am stumped! i have replaced all three relays, tried isolating each compenent and had no positive results. the truck runs fine besides these issues, but with the temp hitting 100* here, i cant drive it without air OR windows! please help!!

deathphoenix99 · 06-29-2009, 01:31 PM

The windows and the a/c are on different circuits, so the underhood relay should not effect the windows at all. I'm going to guess your ignition switch might be going out, as both the windows and the a/c only have power with the key in the RUN position. If you want wiring diagrams to help isolate your problem, then give me your email addy. If they are separate instances, I would check for power at the fuse panel on the side of the dash. There should be a circuit breaker rather than a typical fuse you should check for power at. As for the A/C, you should check for power at the relay you mentioned, also try bypassing the a/c's low pressure switch to see if the clutch will engage.

When your a/c and windows do not work, check to see if your cruise control works, if it doesn't, then that pretty much narrows it down to the ignition switch.

cnomad172 · 06-29-2009, 02:53 PM

hey, thanks for that! i was thinking it had to do with the ignition cycle since the dash lights come on when this happens. i think i remember the previous owner saying they changed something on the ignition, but dont remember for sure. would i need to replace all ignition components in the steering column? or is there a single culprit to target? also, why would banging on the relay temporarily fix this? *confused* oh well.. will try to target the ignition when i get home tomorrow!

deathphoenix99 · 06-29-2009, 03:25 PM

Maybe it was just a coincidence that when you hit the relay you moved the dash area a little bit too. The ignition switch is the only thing you would have to replace, it is located on the steering column, and are known to go out occasionally on GM vehicles.

cnomad172 · 06-30-2009, 10:46 AM

cool.. thought i knew where the ignition switch was.. that's where i put the key, right??

anyway, just got home today, so gonna try to finsd a new switch and see if that does anything. thanks again!

cnomad172 · 07-02-2009, 10:28 PM

ok bro.. thanks! replaced the ignition switch and all is good! has anyone ever tried to find an e4 socket?? not fun.. i spent more time searching for tools than i did working on the truck! anyway, all is good.. thanks again!!

06-29-2009, 12:23 PM	#1
cnomad172 Registered User Age: 31 Join Date: Jun 2009 Posts: 4 Location: User is: OffLine	power windows and a/c elec. issue hey guys, i have a 97 blazer lt with the 4.3l. when i bought the thing about a year ago, it had an occasional issue that when you started it, the a/c and windows wouldn't work. well i sniffed around and found that if i tapped the far left realy of the three on the firewall.. the compressor would kick on and everything was ok. this issue started occurring more and more often. then i had to hit the realy harder and harder. now, when i can get the a/c to come on.. as soon as i hit the power windows everything quits again. i traced the larger purple wire from this relay to the a/c blower. when i unhook the blower and the compressor and try the windows, it just makes the dash start it's whole startup cycle again. this also happened when the a/c would not kick on to beghin with. i am stumped! i have replaced all three relays, tried isolating each compenent and had no positive results. the truck runs fine besides these issues, but with the temp hitting 100* here, i cant drive it without air OR windows! please help!!
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06-29-2009, 01:31 PM	#2
deathphoenix99 94 2.2, feel the power? Age: 19 Join Date: Oct 2007 Posts: 3,000 Location: Houston, TX User is: OffLine	Re: power windows and a/c elec. issue The windows and the a/c are on different circuits, so the underhood relay should not effect the windows at all. I'm going to guess your ignition switch might be going out, as both the windows and the a/c only have power with the key in the RUN position. If you want wiring diagrams to help isolate your problem, then give me your email addy. If they are separate instances, I would check for power at the fuse panel on the side of the dash. There should be a circuit breaker rather than a typical fuse you should check for power at. As for the A/C, you should check for power at the relay you mentioned, also try bypassing the a/c's low pressure switch to see if the clutch will engage. When your a/c and windows do not work, check to see if your cruise control works, if it doesn't, then that pretty much narrows it down to the ignition switch.
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06-29-2009, 02:53 PM	#3
cnomad172 Registered User Age: 31 Join Date: Jun 2009 Posts: 4 Location: User is: OffLine	Re: power windows and a/c elec. issue hey, thanks for that! i was thinking it had to do with the ignition cycle since the dash lights come on when this happens. i think i remember the previous owner saying they changed something on the ignition, but dont remember for sure. would i need to replace all ignition components in the steering column? or is there a single culprit to target? also, why would banging on the relay temporarily fix this? confused oh well.. will try to target the ignition when i get home tomorrow!
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06-29-2009, 03:25 PM	#4
deathphoenix99 94 2.2, feel the power? Age: 19 Join Date: Oct 2007 Posts: 3,000 Location: Houston, TX User is: OffLine	Re: power windows and a/c elec. issue Maybe it was just a coincidence that when you hit the relay you moved the dash area a little bit too. The ignition switch is the only thing you would have to replace, it is located on the steering column, and are known to go out occasionally on GM vehicles.
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06-30-2009, 10:46 AM	#5
cnomad172 Registered User Age: 31 Join Date: Jun 2009 Posts: 4 Location: User is: OffLine	Re: power windows and a/c elec. issue cool.. thought i knew where the ignition switch was.. that's where i put the key, right?? anyway, just got home today, so gonna try to finsd a new switch and see if that does anything. thanks again!
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07-02-2009, 10:28 PM	#6
cnomad172 Registered User Age: 31 Join Date: Jun 2009 Posts: 4 Location: User is: OffLine	Re: power windows and a/c elec. issue ok bro.. thanks! replaced the ignition switch and all is good! has anyone ever tried to find an e4 socket?? not fun.. i spent more time searching for tools than i did working on the truck! anyway, all is good.. thanks again!!
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