2001 Ford Escape. AC cools when started, but when the engine warms up, it ceases to cool. What is the way to fix it?
Wednesday, June 22nd, 2011 AT 1:54 PM
Well, there could be a few problems. The first assumption I would have is that the AC condenser fan is not functioning properly. Turn the Escape on and turn the AC on high. Watch the fan for about 5 minutes after the vehicle warms up and see if it turns on. If it does not, check the voltage going to the fan.
If you have roughly 12 volts going to the fan, then the fan motor has failed. If not, you have a wiring problem somewhere.
The other thing that comes to mind is excessive pressure in the system. This is typically caused by a clog in the system and must be checked by a professional.
So check two things first: a) A/C condenser fan.
B) R134a pressure in the A/C lines. (Professionally done)
Get back to me after you check these.
Wednesday, June 22nd, 2011 AT 2:03 PM
Condenser and fan ok. Pressure has been checked and it ok. Mechanics have not found a problem, but there is one. Any other suggestions.
Wednesday, June 22nd, 2011 AT 2:37 PM
Next step is to check the clutch cycle off times. You need to check the ambient temperature in the engine compartment and then count the number of seconds between the A/C compressor clutch turning off and back on.
The clutch should remain on at the following temperatures for the following number of seconds: 60 degrees F - 20 to 50 sec.
70 degrees F - 30 to 65 seconds
80 degrees F - 45 to 120 sec.
90+ degrees F - 95 - continuously on
If the times are within spec, then the evaporator core is likely restricted. If the times are off continue to the off time test.
When the AC clutch cycles off, it should remain off for the amount of seconds specified for at the temp. Indicated.
60 degrees F - 17 to 24 sec.
70 degrees F - 14 to 23 seconds
80 degrees F - 2 to 17 sec.
90+ degrees F - 2 to 3 sec.
If the times exceed these marks, have the system vacuumed and recharged, as there is moisture in it.