I took out the old 32" LCD TV and replaced it with a 39" Vizio full HD LED TV. 1/3 the weight and less than 1/4 power consumption. In doing so, i rerouted the 6 conductor phone line running from the front AC to the Comfort Control Center. I had to cut the phone line (carefully, one conductor at a time) to move it into the overhead cavity rather than have it drop out of the ceiling. I carefully spliced allthe wires back together and confirmed continuity on each conductor from the plug at one end to the plug at the other. I put it all back together and no CCC display. It appears that there is no 12v DC to the CCC. There is 12v DC in wire #108. There is 12v DC across the red and black wire in the electronics box under the AC cover as there should be. There seems to be no 12v DC in the 4 conductor phone line coming down into the compartment that connects to the 6 conductor phone line leading to the CCC.
I may have inadvertently shorted something splicing the 6 conductor phone line. Is there a fuse somewhere on the AC control board in the electronics compartment?
It is not the 6 conductor phone line, it checks out. Just no 12v DC to the CCC. Any ideas, wise ones?
As always, thanks.
Roger
Hi Roger,
There is a 3 amp spade fuse on the control board for each Dometic roof air conditioner. The thermostat gets it's 12 volt power from the front AC board, so chances are you popped that fuse. The AC boards usually are inside a metal box and may be accessible from the ceiling duct outlet or otherwise from the roof. Trace the phone type cables to find the box.
There also should be another 12 volt fuse for the ACs for your coach. Check under the refrigerator of behind the white panel.
Inverting the phone plug onto the cable definitely will cause interesting problems - like blowing the fuse or a short that can melt phone wires. But that doesn't sound like your concern.
Jim
2002 U320
Thanks, i'll look for it in the AM.
Roger
I went to radio shack, bought a small transformer, 115 to 12 volt, a solid state rectifier and now have 12 volts inside the A/C units to use for the control.
I just pulled the spade fuse from my AC "test jig " board and noted the thermostat still had power. Ah ha! This would suggest you have not yet found the 12 volt coach fuse for the ACs and that the fuses on the AC boards must have not been blown.
Calling James Triana at FOT on Monday may be the easiest way to find the main 12 volt fuse/breaker for your ACs. Does your coach manual show this information?
Often it is a challenge to locate a popped breaker behind the white panel in the basement. Disconnect your added transformer first then use a volt meter to detect which breaker is open. Possibly use a mirror to see the reset button on them - a very small button almost hidden on the side of the breaker. Push it back in. You then should show voltage at the breaker's output and hopefully at the ACs.
I wonder how many decades it takes owners to learn everything about their coach?? How ironic, by the time they do, they begin to forget it all.
Jim
2002 U320
Hi Folks,
Here is what I found this AM. Amazingly, I found a 3 amp fuse in my box of fuses collected over 35 years of RVing. Only one so I have to go buy a box of five or how ever they come these days. I switched off the front and rear AC 110v circuit beakers. DW sent up the appropriate tools in the bucket-on-a-rope elevator once i climbed up the rear ladder. Once access was gained to the electronics compartment on the front AC I found the fuse in the lower RH corner with the help of my trusty LED flashlight. I pulled the fuse and it was blown. I replaced the fuse and replaced all of the covers. Then I checked the rear AC. The fuse there was OK, probably protected by the front AC fuse. Closed everything up and then cleaned the inside and outside oi the Fantastic Fan outside cover and inside crank up cover as long as I was up there. Pretty dirty.
Back inside with tools put away and AC breakers back on I switched on the CCC and there were numbers and letters. Turned on the AC units and they both work. Heat pumps work, fan only works and all four AquaHot zones work. Back in business!
Wire #108 feeds 12v DC to the front AC and through that to the rear. This comes from the front bus 6 Amp circuit breaker #52 behind the panel in front of the passenger's seat, at least that is where it comes from in my coach. I checked voltage at the breaker, in the front cab overhead spaces and at the front AC. 12V all the way. I also verified ground continuity. It wasn't until I replaced the 3 amp fuse that I had power back to the CCC.
Jim, you are right, these coaches are the ultimate puzzle sometimes. It really helps to be willing and able to try to figure out how the systems work, how to diagnose problems, ask for help and at my age write down what we figured out (might not remember it after a while). We are 2 years into owning this coach. There is lots left to learn.
Thanks everyone for your help. I appreciate it.
Roger
Roger,
Well, good! I'm glad to hear you found the blown fuse and the breaker. I appreciate your telling us which breaker it was. Sometimes it is in the last place we look, literally, pun intended.
Jim
I did the same thing as Bill when I replaced my rear A/C with the new Digital Dometic thermostat. The older coaches did not need external 12V for the old thermstat.
Thanks All,
The CCC side line was all due to a TV upgrade. The 39" Vizio 1080p HDTV is great. Much cooler than the LCD TV and much less power required.
Roger,
The TV upgrade looks great but it would sure be nice to learn details and see more photos!
Thanks,
Trent
My Vizio LED TV picture failed one month after the warranty ended. Customer service concluded it was a mother board failure. $75 plus shipping one way to repair. Not an uncommon problem, they said. Remember how long CRT TV's lasted? They didn't know whether coach installation played any role in the failure. Time will tell, I guess.
Amos, I have had my Vizio's LED's for a couple of years no problem. However they don't like power switching (between the gen, shore, or inverter power) neither does the Bose or sat receiver it seems to confuse them. I always turn them off before interupting the power if possable.