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Foretravel Motorhome Forums => Foretravel Tech Talk => Topic started by: Moby on February 19, 2020, 12:35:35 am

Title: No heat from Coleman roof unit.
Post by: Moby on February 19, 2020, 12:35:35 am
Have an older Coleman roof AC/Heat unit giving me no heat. Not a heat pump model.
1)  I replaced the selector/function switch last year.
2)  I BELIEVE but cant prove it was working yesterday after a moving day
3)  Tried cycling temp controller with no success.
4)  Heating element cold to touch.

Blue and orange wires come from element into junction box with selector/function switch. Blue wire connected to another blue wire that exits junction box. Orange wire goes to a pin on back of selector/function switch.

Any suggestions as to where to check voltages (what pins to what wires)?
Resistance across heating element?
Any other ideas?
Title: Re: No heat from Coleman roof unit.
Post by: Moby on February 21, 2020, 09:47:41 am
No suggestions?
Title: Re: No heat from Coleman roof unit.
Post by: DavidS on February 21, 2020, 09:56:39 am
unplug the element and see if its calling for heat through the plug(electric side).. if not element is bad?

Thought Coleman made tents ?  :))
Title: Re: No heat from Coleman roof unit.
Post by: Moby on February 21, 2020, 10:14:33 am
Hmmmm.
God forbid I try the simple stuff first.
That's a duh on me.
Title: Re: No heat from Coleman roof unit.
Post by: nitehawk on February 21, 2020, 10:23:49 am
Coleman is Dometic. Dometic is Coleman. I have two Coleman/Dometic ACs up on the roof of our '89 GV.
Title: Re: No heat from Coleman roof unit.
Post by: nitehawk on February 21, 2020, 10:25:16 am
UH, are you hooked up to 120V? ACs won't run/heat with 12V.
Title: Re: No heat from Coleman roof unit.
Post by: Moby on February 21, 2020, 10:28:17 am
UH, are you hooked up to 120V? ACs won't run/heat with 12V.
Yup.
Title: Re: No heat from Coleman roof unit.
Post by: Chuck & Jeannie on February 21, 2020, 11:47:49 am
The resistance heating element should be similar to ones used in water heaters and electric stoves.

If you unplug the element from the wiring harness it can then be tested for continuity with a multi-meter.

Touch probes to the two male (or female) wiring plug connection points on the element.

If no BEEP (open circuit) then element is bad (burned out).
Title: Re: No heat from Coleman roof unit.
Post by: DavidS on February 21, 2020, 11:55:32 am
Coleman is Dometic. Dometic is Coleman. I have two Coleman/Dometic ACs up on the roof of our '89 GV.

That was a joke .. maybe I should have used a smiley face.. oh wait  ^.^d
Title: Re: No heat from Coleman roof unit.
Post by: Moby on February 21, 2020, 02:10:24 pm
That was a joke .. maybe I should have used a smiley face.. oh wait  ^.^d
We got it.
If you have 2 coleman dometic units, does that mean you have 4 total units up there.
Title: Re: No heat from Coleman roof unit.
Post by: Moby on February 21, 2020, 02:11:15 pm
The resistance heating element should be similar to ones used in water heaters and electric stoves.

If you unplug the element from the wiring harness it can then be tested for continuity with a multi-meter.

Touch probes to the two male (or female) wiring plug connection points on the element.

If no BEEP (open circuit) then element is bad (burned out).
AND I can verify the element is getting 120
Title: Re: No heat from Coleman roof unit.
Post by: Caflashbob on February 21, 2020, 09:27:25 pm
I have had Coleman heating elements fail in coaches long ago
Title: Re: No heat from Coleman roof unit.
Post by: Michelle on February 21, 2020, 09:46:24 pm
I have had Coleman heating elements fail in coaches long ago

And just how is that helpful to the original poster who is trying to diagnose his units?
Title: Re: No heat from Coleman roof unit.
Post by: Caflashbob on February 22, 2020, 01:12:39 am
Of course you are correct.  No help at all.

Replaced dozens of elements and maybe a few controls.  I came from Coleman days long ago