Cadillac Repair: Cadillac Air Conditioner, light dims, dash vents

Question
Hi,

1999 Standard Deville.

Air conditioner problem.

Set on automatic at 60 or 65 degrees with fan on automatic.
The air conditioner blows cold.
The cabin is nowhere near 65 degrees.
The dash vents will blow air for a few minutes and then
start cycling on and off.
The air will come through the dash vents for about a minute and
then shut off for about two minutes, then come back on through
the vents for another minute. The compressor is still cycling while
this is happening.
No trouble codes are stored.

Answer
Hi Robert,

      Since the fan turns on and off what happens if you manually turn the fan to hi or low does it turn back on? If it does the in car temp sensor might be reading the incorrect temperature but without having a scan tool to test it you won't know for sure.

     If the fan doesn't turn on then it sounds like the fan might be going bad. On that type fan the fan module is incorporated inside so you would have to replace the fan. To test the fan you would need to use a test light or voltmeter on the heavy gauge red and black wires and command the fan speed low to high and see if the voltage changes or light dims and brightens. If it does then the fan will need to be replaced. Otherwise more testing will need to be done.

    Hope that helps get the fan working correctly. And let me know if you need more help. Bill