A/C help on Thermoking

First of all with the front cover off. Get a test light and turn the unit on and select A/C mode. When the unit starts text the wire to the compressor clutch and see if it’s getting power.
Secondly when you had the leak I’m sure you lost some oil if not all oil with the Freon. My question is who repaired your lines after the leak? Did they check and add compressor oil? Because if they didn’t you may have a overheated bad compressor due to lack of oil.

 

Thermoking themselves did all the repairs. The condenser was bad and leaked the majority of the Freon out. They replaced all the parts including the condenser fan. It looks to be that the compressor clutch is receiving power. The 7.5 amp fuse for the compressor clutch is also good. Not sure what the issue is. I don’t see any evidence of a leak. Freon levels look normal as per gauge check.

 

I had the exact same issues with one of my trucks. It turn out they didn’t put oil in the compressor after repairing the leak, the A/C worked for months the the compressor overheated and went bad, it was doing the exact same symptoms you described. There was power to the compressor clutch. The unit will run fine without A/C selected but as soon as you turn on A//C immediately after the condenser fan comes on it will shut off and ACS code displayed.

 

AC5 sets for one of three reasons...

1. Low refrigerant. (Trips code instantly)
2. High side pressure too high. (Can take a minute to set this code... usually condenser fan inop)
3. Bad binary switch.

How much static pressure is in the system? Is the compressor locked up?

 

If it would have low Freon, how could it be refilled if it shuts off instantly? Just curious.
High pressure side seems normal and switch is new.

 

When was the unit built?

Before 9/2006 they used a binary switch. More than 325 psi on the high side or less than 22.5 psi static pressure would set an AC5 code.

After 9/2006 they went to a separate high pressure cutout switch which would set AC5 over 400 psi. The low pressure cutout would disengage the clutch at less than 5 psi but the unit will still run.

If you don’t have AC gauges or a pretty good understanding of how AC works, I would just take it back to TK (or a dedicated AC shop).

 

My tripac was trying to run in AC mode, yet after three times of the compressor engaging for a few seconds the unit would shut down. I noticed the condenser fan, the one on the exterior of the truck in the back, was not coming on when the compressor engaged. Tracked it down to a 20A fuse in the "black box". Replaced the fuse and all is good. Hope this helps someone.

 

ThermoKing will tell you that a bigger fuse may help, going to a 25 amp. Worked for me for about 3 weeks, then the motor locked up. If the fuse blows, you probably have a problem.

 

That's what I'm watching for and I agree, once could be an anomaly but twice it goes into the shop. Fan seems to move freely so maybe had a stick or something binding it up at some point. Anyways I'll be staying with the 20 amp too. See what happens.

 

Do you know what size lines they use? I’m needed to replace them starting to ware