1998 ford ranger. AC dosnt work anymore. I thought it might be low pressure and tried to add a can. However it would take any R-134. Saw that compressor wasnt running/ clutch wasnt kicking in. Thought is was a bad compressor/clutch. Removed compressor and put 12 vots to clutch and it kicked in. Reinstalled compressor and now it seems to work fine. Added a charge to it and everything worked OK for 2 days.

Now its not working again. If I disconnect the clutch I can measure 12 volts when AC is turned ON/ 0 volts when off and so on. Tells me the circut is working unless there is enough current for clutch. If I connect to the clutch volts goes from 12 to 0, disconnect clutch it goes back up to 12 volts. I can do this as often as needed. As soon as the clutch is in play the potential drops to zero. Which it would be anyway if the clutch was energized.

Clutch resistance is 6 ohms, this tells me that either; 1. I have a bad coil in the clutch (not too likely since I measure 6 ohms) 2. there isnt enough current being supplied by what ever circut supplys it for the coil to move the clutch. 3. sticking clutch that wont pull in with availiable current,or 4. I have a leak somewhere that, that some sensor knows about and when the clutch is connected it somehow reduces the current going to the clutch coil so it dosnt pull in.

(incidently if I connect directly to the battery the clutch pulls in just fine)

I read 100 PSI at the low and high side with the system off, have so for two days.

Looking for any advice or ideas to try.............

 

I forgot to add that if I short out the low pressure switch the AC clutch still wont kick in but the cooling fan for the radiator turns on.