AC dead

[Greg Ross]

I was cooling the coach in preperation for leaving on a trip when the AC died, no power to thermostats and 15 Amp fuse in toilet room blows as soon as I replaced the fuse (short) I installed a 20 Amp fuse and it lasted about 10 seconds.
I disconnected the power at both ACs on roof and still short circuit,
Replaced relay behind wood panel (why would you need a relay here?) sttill dead short.
There must be a control of some kind which is common to both ACs where I think the problem is but I do not know where it is,anyone with any ideas?
Thanks
2008 Contessa

[Steve Huber]

If this is occurring on a single AC, you may have s frozen compressor.
Steve

[Greg Ross]

Both ACs are dead

[Steve Huber]

Greg,
Since the AC circuit breaker are not tripping, it is a 12vdc control issue. 1st, never put a higher amperage fuse in place of the designed one unless you want to risk causing more issues and possibly a fire. You noted you replaced a fuse in the toilet box. If it was F8, it feeds the thermostats, the satellite power and the TV booster. So the excessive load could be coming from  one of the latter 2 loads and not the T'stats. Try disconnecting each of those loads to see it thermostats/ACs work. If it wasn't F8, which fuse was it?
Steve

[Greg Ross]

The fuse was F8 but it does not feed a tv booster or satilite that I know of.
Does anyone have a good wiring diagram, the ACs are Penquins.
Thanks

[Steve Huber]

Greg,
Refer to the lower right corner of page 167 in your 2008 Contessa Owners Manual.
Wiring diagrams and Owners Manual are located in Coach Assist.
Steve

[Joel Ashley]

What’s your connection to external power like, Greg?  If you have too much voltage drop, your AC unit(s) need so many watts to be efficient, and will pull extra current under diminished voltage conditions in order for V X L(current) to = W. 

Too long or small of a cord between source and transfer box, or a weakened adapter between cords, or a burned outlet plug or damaged cord can lose you significant volts.

Joel

[Greg Ross]

Power is Good

[Greg Ross]

What I need is a secquence of operation and if possible a 12 volt schmatic for the ACs
Thanks for all your responses.
Greg

[Steve Huber]

Greg,

The 12v circuit is used to power your thermostats. If they don't have power the ACs won't work.

Coach Assist has a manual for a 5 button thermostat. It shows that 12v to the thermostats comes from the AC control box. I assume that it is in the AC unit up top and a 10 or 12 button unit would be wired similarly.

My approach would be to unplug the phone cable from the back of both thermostats and see if the fuse holds or blows. If it blows, the problem is with one of the other 2 circuits if feeds; TV booster or satellite TV,. If it holds, plug one of the T'stats in at a time to see which one is causing the issue.

12v to the control box is probably coming directly from the fuse, which is why it isn't shown in the wiring diagrams. You can also Google your thermostat part# to see if you can find a manual on it.

Steve