A/C turns on and works at times other times is does not.
Could it be that the a/c problem is noticed more on hot days when a malfunction would be more noticable?
It is doubtful the window problem is related to the a/c problem. But a window that doesn't operate might also be more noticable when you are hot and the a/c isn't working up to par you will be more likely to use the window. But hotter temps have physical properties that might raise resistance in a circuit, or the connections can be affected by the expansion of metal in the plug connections or within the window motor itself. Take some tuner cleaner to the toggle switches it will help if the contacts are dirty. Or a good whack on the door panel where the motor is might get it functional for a while.
If the compressor is kicking in and out it is probably the high pressure cut off switch doing its job.
Usually you want to check the freon pressures to see if it is low. By deduction my guess is its probably not a low freon situation if you usually get good cooling. Hot weather only increases the pressures, so a low pressure problem would theoretically improve.
There are 2 things I suspect, but I am not familiar with your specific vehicle, so this is a generic troubleshooter.
This is my checklist in order of likelihood, provided you aren't low on freon.
Overheating condenser coil-gets too hot and not able to dissipate the heat exchange efficiently. This raises the pressures until the high pressure cut out switch cuts the compressor off. When the condenser cools off pressures normalize and the hi pressure switch disengages, allowing the compressor to compress again.
CAUSES: Clogged condensor radiator fins- clogged with bugs & debris. Clean with high pressure to get the bugs out. Flush them out from the inside to the outside so the don't get lodged deeper in the coil.
Bad condenser fan; bad fan relay, blown fuse or open in circuit.
Clogged condenser coil- Internal blockage. May require condenser replacement, but radiator specialist maybe can by pass the bad spot depending on where it is - may get frosty near blocked area.
Overheating condenser will show up when you are stopped in traffic, but when moving- especially at hiway speeds- you push air through the condenser, which cools it and lowers the pressure, keeping the Hi pressure cut out switch from engaging. Does the belt squeal just before the compressor cuts out? This is a sure sign of a overheating condensor.
The condenser fan cools when you're not moving. Depending on your setup your condenser fan may not be on all the time. On older domestics the condenser is behind the radiator and the radiator fan cools both. On most foreign & newer cars the radiators are side by side with separate electric fans for each.
HOW TO TROUBLESHOOT THE CONDENSER. Start your car, open the doors wide and turn on the a/c on HI. Let it run until the compressor cuts out. Take a garden hose and run water over the condenser- does it steam a lot when the water hits it-then it is probably overheating- Continue to run water over it- DOES THE COMPRESSOR KICK BACK ON WHEN THE CONDENSOR COOLS OFF? If yes, your condensor is overheating.
Remove the water and let it run until the cut-out switch engages again. DOES THE CONDENSOR FAN ENGAGE AT ALL DURING THIS PROCESS? If Yes: Is it blowing normally or sub-par? If blowing normally the fan and circuit are working properly.
IF NO- the problem is a bad fan or fan circuit. Test the fan by disconnecting the 12vdc plug and jumping with 12 volts from the battery. DOES THE FAN WORK WHEN YOU JUMP IT? IF NO- your condensor fan motor is bad- replace it. IF YES- the fault lies in your condenser fan circuit. check fuses, relays, etc for that circuit.
If this isn't your problem here are more some things that may be going wrong, depending on your cars components and configuration.
Clogged condensor coil- flush debris with air or water pressure to the front. Clogged orifice tube or other component depending on what your system has. This is not exhaustive, but it is the most likely culprits.
Good Luck and rate this solution please
May 02, 2009 |
1999 Chevrolet Suburban