'98 A.C. problem
#1
09-23-2009, 03:40 PM
'98 A.C. problem
After baking in the sun the A.C. compressor won't run. The AC works fine in the morning. Leaving work on a hot day the blower runs and the dash light is on but the compressor and condensor fan will not run. After it cools off it will work. I've had it start working on the ride home.
The compressor, filter, expansion valve, and condensor fan have all been replaced in the last six months.(when I bought it)
The wiring diagram in the Haynes book is generic and says I have an AC amplifier which I have not seen.
Any suggestions?
Thanks
Paul
The compressor, filter, expansion valve, and condensor fan have all been replaced in the last six months.(when I bought it)
The wiring diagram in the Haynes book is generic and says I have an AC amplifier which I have not seen.
Any suggestions?
Thanks
Paul
#2
09-23-2009, 09:11 PM
The AC amplifier is for the blower motor fan speeds and is not likely the problem if the AC light is lit. The evaporator has a thermostat to cycle the compressor. It is a 2 wire switch so you can jump the wires when it is not working to check it. There are also several relays under the hood to control the compressor clutch/condensor fans which could be an issue.
#3
09-24-2009, 01:07 PM
Thanks for the reply. The only relay on the fuse and relay panel on the drivers inner fender is labeled "Cooling fan". Is there another somewhere else for the condenser fan and AC clutch? Can you describe where it is?
The switch you mentioned as on the evaporator, is it in the housing with the evap. and expansion valve, or is it outside?
Is a wiring diagram available short of the dealer?
Thanks
Paul
The switch you mentioned as on the evaporator, is it in the housing with the evap. and expansion valve, or is it outside?
Is a wiring diagram available short of the dealer?
Thanks
Paul
#4
10-15-2009, 03:32 PM
Check the following:
1. When the problem apparent, see both A/C fan & Radiator cooling fan working. Both should work if the engine is hot enough and A/C is on.
2. While looking at the A/C compressor clutch, ask someone to turn on and off A/C at the dashboard. If the clutch is not engaging within 2 sec. power to the magnetic clutch will be disconnected. This is an interlock protection used in the modern A/C systems. If this is the case you need to re adjust the gap between magnetic clutch assembly and compressor pulley. The gap should be not more than 0.8mm when hot.
The gap can be adjusted using a thinner flat washer beneath the clutch mounting bolt.
3. Check for the proper refrigerant level. (Hi side & Low side pressure) If it is low, A/C compressor will not engage.
Good luck.
1. When the problem apparent, see both A/C fan & Radiator cooling fan working. Both should work if the engine is hot enough and A/C is on.
2. While looking at the A/C compressor clutch, ask someone to turn on and off A/C at the dashboard. If the clutch is not engaging within 2 sec. power to the magnetic clutch will be disconnected. This is an interlock protection used in the modern A/C systems. If this is the case you need to re adjust the gap between magnetic clutch assembly and compressor pulley. The gap should be not more than 0.8mm when hot.
The gap can be adjusted using a thinner flat washer beneath the clutch mounting bolt.
3. Check for the proper refrigerant level. (Hi side & Low side pressure) If it is low, A/C compressor will not engage.
Good luck.
