SOLVED: No power getting to the thermostat

[rejesterd]

SOLVED: It was a short somewhere between the blue wires at the furnace and the tstat. Refer to this post

Hi All,

1997 Terry 30g RV with an Atwood 8531-III DCLP furnace and a Coleman 7300 air conditioner.

I just opened up my camper for this season, and found that power is not getting to the thermostat. The heat, AC nor the fan work. The last time this occurred, it was due to the small 2A fuse on the thermostat itself. However, i removed it today and it has continuity and the connection points look clean. This is an older Coleman thermostat..



I can confirm that I get 13.something volts at the circuit breaker on the furnace.



I checked the voltage at all 3 connection points to that breaker (the 2 red wires and the blue wire).

What would be the next step to troubleshoot this further?

Thanks as always.

[BFL13]

You need a ground to get the 12v on a meter at the tstat, The two blues from the furnace are actually cut and joined at the tstat switch in a heat only. with an air conditioner it seems the wires all go to a relay up thee and back so it is red and white. Anyway, you can confirm the furnace works down at the furnace by jumpering the blues that would go to the tstat (but somehow get to the red and white on yours I think)

Too confusing, but here is a thread on that that might help including links to trouble shooting.

https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/30000743/srt/pa/pging/1/page/4.cfm