i don't claim to know everything about ac system but this has me a little confused.... when the ac in turned on it blows ice cold for like 30 seconds.....then warm.... turn it off for a min.... turn it back on and it is ice cold angain for 30 sec.... i can do this over and over... what would cause that????

 

I don't know about our car, but other cars I've worked on have a Thermal Protection Switch on the A/C compressor that keeps the compressor from spinning if it gets to hot. Common cause is too much coolant in the system.

Pop your hood with the engine running. Turn the A/C on. Revs should jump up, A/C should kick on. After the A/C goes warm again, if the engine is still running with high revs, it's probably the TPS. If you look at the clutch on the compressor, it shouldn't be spinning.

Other option is that you don't have the right amount of coolant in the system. Put a pressure guage on it and check.

 

make sure the fans are turning on. does the compressor cycle? are the evap lines icing up? yet another prob you will prob need a the right tools o diagnose. a set of gagues would be helpful

 

thanks guys... i will def. look into it..

 

Will the A/C cut back on if you leave it on or do you HAVE to manually turn the switch off and on to get it to cycle? If it takes 15-20 sec between cycles, it might just be low on freon. To test this further, jump the pressure switch with a paperclip and if the vent temps stay cold, you are very likely low on freon. Guages are the best way to test but this will do in a pinch. If that doesn't solve it, time to look at the clutch coil and relays.
Hope this helps,
David
PS: Do not leave the switch jumped for more than a few minutes or you will burn up the compressor!!

 

My A/C didn't work suddenly today after it was turned on for few minutes. I have check and replace the fuse, no blown fues. When I check my PFC commander, the sensor doesn't shows any signal even I push the A/C button on and off. What could cause the A/C not turning on.

BTW my A/C was working great and no leak until this afternoon when I turned in on on the FWY at 95F+ degree.

BC

 

u have a bad thermo switch behind the evaporator or it could be dirty or could be a freon level problem.

 

Thanks I will check those

BC