Anyone know where the relay for the AC compressor lives? Not listed for power dist. box. Is there another panel somewhere.

E-350 1999

 

Looking over my printed EVTM for both a '97 and '00 E-Series I show only one fuse for the A/C system, its #13 in the inside fuse panel. There are two pressure switches which will prevent the compressor from engaging if they don't see their desired pressures---could you have developed a refrigerant leak perhaps? Do the blower motors work?

If I'm wrong on this someone will certainly correct me---my info might not be complete.

 

Fuse is good. Blower works but compressor clutch is not engaging... Not rotating. By pressure do you mean AC. Needs refrigerant to be there to operate compressor?

 

Yes---one switch inline to only let the compressor engage when there is a pre-set pressure in the system and another to trip out if that pressure gets too high. Your symptoms suggest your refrigerant is low.

If the clutch is engaging but not rotating that would mean the compressor is seized and would be making one helluva squealing from the belt---is that what's happening?

 

No. No rotation at all. No kick in of compressor when switch set to AC. Will check coolant pressure if possible.

Update: added what was left in a can of 134a and compressor came on but seems to cycle on/off. Will buy another two cans and add more. Have a gauge to check pressure. Says I'm not there yet.

 

Yes you were apparently low enough on refrigerant that the low limit switch wouldn't allow the compressor to engage. This is a safety feature on most every A/C system--without it the compressor doesn't receive lubrication or cooling from circulating refrigerant and oil in the charged system.

I did forget to ask if there are any signs of oil being deposited near any of the A/C fittings or lines?

You can also post this to the A/C forum where someone can give you an idea how to make sure you have enough oil in your system.

Update: Hey Scooter---found this:https://www.ford-trucks.com/forums/1...t-kick-in.html