1997 Explorer EB V8 with EATC. Need some AC troubleshooting please. AC worked great after recharging by shop. AC runs very cold on vent with auto temp set until on longer trips/highway speeds, the air will turn warm. The rear AC still blows cold. Changing temp does not help. Switching to def/floor/dash/max ac feels like hardly any air blows in any position.

The fan speed works on vent when this happens, it did not appear to have any affect on the other positions. The compressor still sounds like it is engaged. No odd noises.

Prior to AC recharge, I replaced the blend door and removed a shim from the fan clutch (only appeared to be the one).The cooler lines at the firewall are ice cold.

After the engine has been off for a while, the AC works again.

Your guidance is appreciated. I am not sure what and where to start checking.

 

Check for an iced evaporator. Next time if fails, park the vehicle and see how large of a puddle forms under the drain after an hour or two.

 

I will check the evaporator the next time and hope to post back. Thank you.

 

Replaced the AC cycling switch since it was a cheap part. The old part did not have a rattle when shaken; the new one did.

I was able to finally replicate the problem of AC running at great flow and cold. After awhile driving at highway speeds, the air flow stopped. Rear unit still blows air. Opened the hood, and voila, the AC receiver/accumulator is iced over.

What should I check for now? Would removing a AC Clutch shim cause continuous cycling and icing? Again, this is a 97 Explorer EB with EATC.

Any suggestions are appreciated!

 

If the removal of the shim resulted in "no gap", then, yes, it could cause this problem.

I'd suggest that you verify that the clutch properly disengages when the climate control is turned OFF and that the clutch engages again properly when the A/C function is re-selected.

 

Thanks projectSHO89, replacing the shim is first on the list. I will report back.