dimming headlights with ac
02-23-2015, 08:27 PM
#1
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Car: 1991 Camaro RS
Engine: V8 5.0
Transmission: 5 Speed
dimming headlights with ac
I notice when I run the ac all lights dim down as well as rpms dropping and it does this and it does this on and off about every 5 seconds.. also idk if its related sometimes on cold starts the car takes longer to turn on rather than right away
02-23-2015, 11:48 PM
#2
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Car: 86 Trans Am
Engine: 305 LB9
Transmission: 700r4
Re: dimming headlights with ac
May be an alternator issue. I'd have it tested. However my car does this and similar problems but the entire charging system is new. Just wasn't made to handle all the load since ac wasn't even standard
02-24-2015, 08:41 AM
#3
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Car: 88GTA
Engine: 5.7TPI
Transmission: Auto
Axle/Gears: 3.27
Re: dimming headlights with ac
Check your idle speed for one.
When you turn on the AC, it pulls from the engine and brings the rpm's down even further. The every "5 second thing" is the AC cycling on and off. If it cycles every 5 seconds, it may need a recharge. The pressure sensor on the AC line may be sensing LOW FREON on the system, telling the AC to cycle back off. Then the cycle repeats itself again.
When you turn on the AC, it pulls from the engine and brings the rpm's down even further. The every "5 second thing" is the AC cycling on and off. If it cycles every 5 seconds, it may need a recharge. The pressure sensor on the AC line may be sensing LOW FREON on the system, telling the AC to cycle back off. Then the cycle repeats itself again.
02-24-2015, 08:53 AM
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Car: 1 Owner 1986 TA with a WS6 package
Engine: 5.0 EFI
Transmission: THM700R4
Axle/Gears: 277 Posi Speedo
Re: dimming headlights with ac
Check your idle speed for one.
When you turn on the AC, it pulls from the engine and brings the rpm's down even further. The every "5 second thing" is the AC cycling on and off. If it cycles every 5 seconds, it may need a recharge. The pressure sensor on the AC line may be sensing LOW FREON on the system, telling the AC to cycle back off. Then the cycle repeats itself again.
When you turn on the AC, it pulls from the engine and brings the rpm's down even further. The every "5 second thing" is the AC cycling on and off. If it cycles every 5 seconds, it may need a recharge. The pressure sensor on the AC line may be sensing LOW FREON on the system, telling the AC to cycle back off. Then the cycle repeats itself again.
02-25-2015, 10:10 PM
#5
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Re: dimming headlights with ac
The IAC should step up the idle speed to compensate for the load put on the engine by the compressor.
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