So, the clutch has stopped engaging on my 91 V6 4x4 4runner. Today with the engine running I applied 12v+ to the blk/wht wire leading to the clutch, the good news is the clutch engaged, the bad news is I have a problem somewhere else. I did a quick ohm check of all fuses in the 4 different locations around the 4runner but no joy. Before I dive into the relays, thermistors and whatever pressure switches may be around I thought I'd ask to see if anyone had found a "typical" cause for this problem. My haynes shows a "AC Amplifier" providing power to this blk/wht wire but I haven't found that, is it part of the ECU? Thanks in advance guys.

 

I assume you are talking about the AC compressor, not the fan clutch.

This will happen if there is no refrigerant in the system. If that is the case, you likely have a leak to fix before you fill it back up.

 

Yep sorry I was distracted Just the AC clutch. I'll check the pressure before gutting the rest of the electrical system I guess.

 

Yep, no freon in the system. I'm a little ticked because they filled it twice last year with r12 after "finding and fixing the leak". Now they think it's in the evap core. I'm going to expose the core and then figure out what to do from there. This was 2 chances for Brakes Plus to get it right, anyone have experience with Arizona Mobile Air Inc ?