T180 A/C Problems

[calypso428]

Hey guys . Hope everyone has been doing well! I'm having a problem with my a/c . it's been working great all summer long and all of a sudden yesterday the compressor stopped spinning . I got my shop manual and my volt meter and started checking things out . the compressor is showing resistance so I think it's still good . I hooked up a meter freon refill from autozone and it was reading an extremely high pressure in the red zone on the meter so I let some freon out until it was down in the green just in case that was the problem . I also checked resistance on the pressure switch and the thermostat both were good. Also the switches are all good. So . now I'm at a loss . any ideas ? I couldn't get the loader harness to show a 12 volt supply to the compressor or the pressure switch . oh and I checked all fuses and replaced the relay for the ac with no result. I also cannot find any spots on the wiring harness where it could have rubbed through a wire. Thanks Tee -

 

[calypso428]

*UPDATE* So while I had some down time tonight I decided to delve a little deeper. I removed the cover from underneath the cab that protects the air conditioning coils. I checked the fan and the thermostat and I have a reading for 12v power and resistance to both. Double checked the pressure switch and the compressor power and had no 12V but I DO have continuity.... So that means that the problem has to be somewhere else. As I said before I thoroughly checked the fuse box and the relays and fuses are all good, no problem there. So I decided to pull out the AC controls from inside the cab and See if my switches were bad and if I have 12V supply to them. AC switch was good and so was the temp control. However something I didnt notice this morning was the 12V power supply wire going to the fan switch was slightly melted on the loader harness and the back of the switch is a little burned and has a loose terminal now. So im going to order a new switch and see if that does the trick. Can I buy a switch like that locally or should I just order one from allskidsteers.com Also should I replace the slightly* melted connection on the loader harness side? Ill have to cut the entire thing off and solder every one of them back together which seems like a pain . Why would that wire have melted and not popped a fuse ?? I hope this is the problem but the pessimist in me says thats old damage from a previous owner. Also why would the fan work fine if this was the problem?? The only thing not running is the compressor. Thoughts ?

 

[Tazza]

*UPDATE* So while I had some down time tonight I decided to delve a little deeper. I removed the cover from underneath the cab that protects the air conditioning coils. I checked the fan and the thermostat and I have a reading for 12v power and resistance to both. Double checked the pressure switch and the compressor power and had no 12V but I DO have continuity.... So that means that the problem has to be somewhere else. As I said before I thoroughly checked the fuse box and the relays and fuses are all good, no problem there. So I decided to pull out the AC controls from inside the cab and See if my switches were bad and if I have 12V supply to them. AC switch was good and so was the temp control. However something I didnt notice this morning was the 12V power supply wire going to the fan switch was slightly melted on the loader harness and the back of the switch is a little burned and has a loose terminal now. So im going to order a new switch and see if that does the trick. Can I buy a switch like that locally or should I just order one from allskidsteers.com Also should I replace the slightly* melted connection on the loader harness side? Ill have to cut the entire thing off and solder every one of them back together which seems like a pain . Why would that wire have melted and not popped a fuse ?? I hope this is the problem but the pessimist in me says thats old damage from a previous owner. Also why would the fan work fine if this was the problem?? The only thing not running is the compressor. Thoughts ?

A bad connection to the switch could be the issue.
When my ac was dead on a new to me machine, i jumped the pump so i knew that the compressor worked. One side from the compressor was hot, one was cold coming back in. I then traced and found a bad connector at a relay that melted.
If it was a hot day, the pressure would have been higher, i wouldn't have dumped out any of the gas, hopefully your AC will still work properly when you fix the issue. You really need a proper set of gauges to know the high and low side pressures when running if there is too much gas in there.
Is the fan working? or no fan, no cooling as well?

 

[calypso428]

A bad connection to the switch could be the issue.
When my ac was dead on a new to me machine, i jumped the pump so i knew that the compressor worked. One side from the compressor was hot, one was cold coming back in. I then traced and found a bad connector at a relay that melted.
If it was a hot day, the pressure would have been higher, i wouldn't have dumped out any of the gas, hopefully your AC will still work properly when you fix the issue. You really need a proper set of gauges to know the high and low side pressures when running if there is too much gas in there.
Is the fan working? or no fan, no cooling as well?

The fan works and blows normally however the compressor doesnt kick on and the air is just warm. No cooling.

 

[Tazza]

The fan works and blows normally however the compressor doesnt kick on and the air is just warm. No cooling.

Try running +12 into the wire that powers the clutch on the compressor, this will confirm that the clutch is still good. Then go to the thermostat/switch.

 

[calypso428]

Try running +12 into the wire that powers the clutch on the compressor, this will confirm that the clutch is still good. Then go to the thermostat/switch.

I tried running 12+ directly to the compressor and it didn't click or anything ... Which made me think it was the clutch . however I replaced the thermostat and that fixed it . also had a leaking o ring on high side at the compressor . it's working great now !

 

[Tazza]

I tried running 12+ directly to the compressor and it didn't click or anything ... Which made me think it was the clutch . however I replaced the thermostat and that fixed it . also had a leaking o ring on high side at the compressor . it's working great now !

That is very odd that the clutch didn't engage..... Hey, never complain about a repair that just involved a new thermostat