Carrier Comfort Pro Apu

Apu initially tripped. I reset breaker. AC now does not come on. Can't change it at display. HVAC says off. 20 amp fuse on back panel under cover of apu is fine. AC blower not working. AC fan on outside not working. Fridge also has defrosted. Fridge started defrosting when Apu tripped. Microwave not working but all outlets work. Apu starts and charges batteries but can't turn on AC at display. Just bought multimeter a few mins ago. Are there any other fuses I need to check? Not sure how to use multimeter correctly and/or how to check voltage. Of course I'm no electrician and I don't want to do something dumb. Any help will be grateful. All belts are fine. All plugs are right I'm assuming.

 

These Carrier APU’s are garbage. Mine has worked properly for about three weeks in the past year. Glad I can idle my company truck.

 

Trying to figure it out so I don't have to go to carrier and get rxped

 

I have a Dynasys so might be a little different but, at the batteries should be another fuse where the power wire for APU is. Really shouldn't need a volt meter to check that, just open the holder and see if the fuse is fried.

 

Thx. Didn't think about that.

 

If that fuse is blown the APU wouldn't even start, that's where it gets it's power from it doesn't have its own battery.

 

Capacitor is shot. Fuse is fine

 

Now that you said that I remember one on a truck i drove doing that, haven't had a APU in year's only run a generator now and will never go back.

 

On a side note, you need to pull every single fuse in the box(es), when searching. I lost every light at the back, except the right turn signal. All my light-related fuses were good. Our tech found a slot marked with three letters I can’t remember, but, that fuse was blown. What the letters meant and why every rear light wasn’t on it, we’ve no idea. He said they’ve gotten in the habit of pulling every fuse, when searching for answers.

Glad you found your answer. I hope this underwhelming ThermoKing APU never gives me issues, even though I know it will.

 

Yea it's totally separate from the truck lights. Apu has fuses in the Apu box and under the bunk. A 4 day headache. Tested the CCU board and boom 4.6 volts. That's how I know capacitor is bad