The first thing that you should check is the wiring going to the blower fan for the front evaporator. If that's not the case you should unplug the fan turn your key on turn the fan on high then check to see if you got 12.6 volts at the connector. If you do replace your blower fan. If not it is possibly a power control module for the blower fan. You should have a technician verify that before you buy that because it is a coslty item.
Hope this helps.
changed battery engine light stays on
Check the ignition coils and the crank sensor for the Yukon. Either one of these could be bad and cause the problem.
If a 1988 Lincoln Town Car is blowing both hot and cold air when the air conditioning is on, there could be a problem with the thermostat. There might also be a problem with the level of refrigerant in the air conditioning pump.
My 2001 had the same problem. There is a GM recall to replace the sending unit.
I have the same problem with my 01 yukon. I heard that cleaning electronic throttle may help. pls let me know if that solution works for you.
That varies with the problem. Could be immediate, or could take a week.
You could have a short from the controlls to the fan
there could possible be hockey
what did it do after you added R134a?
It could be a dead animal somewhere in the engine compartment. May have even possibly gotten into the A/C hoses.
A 1999 Yukon might wobble and vibrate at 55 miles per hour if there is a problem with a wheel. There could be a tie rod loose, bad ball joints, or even a tire that is out of balance. Also check the motor mounts.
Could be a swollen prostrate