2001 Freightliner no power to AC compressor please help!!

Look on top of dryer and unplug wires to see if power is getting that far, if it has 12v. there you may cross the wires temp. to ck. if ac. clutch kick on?

 

Check your low pressure switch if it has one.

 

Get a multi meter, test light or power probe. Do you have a/c gauges?

 

Had lots of problems with the fuse block on the dash that fed the compressor. Wiggling the big fuse might make it start or stop. Eventually a burned terminal underneath the block had to be repaired/replaced.

 

In addtion to what was already mentioned, some older FLD's had an air pressure swtich that would not allow A/C until air built up enough for the fan to work properly. I've only seen that on air engauged fan hubs.

 

2001 FLD has a/c control box and it is the same one that goes on early version centuries. 12 v positive wire goes from that box to fuse box and from there to a/c clutch. also there is a diode on positive wire on fan clutch. a/c control box is located in dash on passenger side and sometimes under cab- right front corner( under passenger foot). its a cigarette box size piece and costs $120 at dealer.

 

There's two switches in the clutch circuit, a high pressure and a low pressure. Either one of those is bad, you won't get power to the clutch.

 

If you don't have power at compressor go to the binery/trinary switch. Gotta have power in and power out. If power in and none out bad switch or low on Freon. If you keep backing up with tester will find problem. My old pete 359 has an off on fan switch witch has to be on for AC.