I have a 93 Breakaway with a Dometic fridge that will no longer select the 12v option. When ac is not available it goes straight to gas. Any ideas?

On ours, there is an on/off switch for the DC. Is yours turned on?

Yes the switch is in the correct position. Thanks

Are you sure you have DC power to the fridge? Maybe a fuse, etc?

My frig has only 110 AC and gas... I think I may have some documents for it that may cover DC also...

There will be 2 electric elements - one for 120 VAC, the other for 12 VDC. Check the connections to the 12V one. If they're good,check the resistance with it disconnected. Resistance should be ~0.5-1.0 ohm.

If the element is open or shorted, the control board won't switch.

Finally, note that if you're using the "auto" feature, the order is AC, LPG, 12 VDC. If the CB senses and can light propane, it won't switch to 12V.

Yes it has 12 volts. As I understand it there is a sensor that can tell when the battery is being charged & will only allow the fridge to run on 12 v dc when charging occurs. I am thinking this might be the problem but
i dont know how to check for it.

Ok I will try to test the 12 volt element. With gas shut off & engine running & selector set on auto the fridge goes into failure mode

quote:

Originally posted by Darryl Kathy Smith:
I have a 93 Breakaway with a Dometic fridge that will no longer select the 12v option. When ac is not available it goes straight to gas. Any ideas?

according to our to your statement,when ac is not available it goes straight to gas,is what my dometic does,as it is supposed to.wally vanisle.

quote:

As I understand it there is a sensor that can tell when the battery is being charged & will only allow the fridge to run on 12 v dc when charging occurs.

Not quite - it has a low-voltage sensor that shuts off the 12 VDC if the battery's low.

Ours only run on 12V with the engine running.

Are you able to tell-us which fridge you have with model number.

Can you supply a photo?

Photo of the control board.

Photo of the eyebrow.

I have recently replaced both the control board and eyebrow in mine.

Don't want to thread wander but Medic did you get everything working after your overload.

Ok, it is a Dometic model RM4804. On this model the selection process is AC first, DC second (if engine is running) then gas.

Ours was a Dometic Royale but the model# went with the new owner. First selection was automatic (1st AC if hooked up or genset, 2nd choice gas and 3rd 12V if engine running), second selection was A/C or gas and third button gas only. ALSO 30 MIN time delay to light gaas after running engine.

Brain pfart - my Norcold will run on 12 VDC without the engine running; it has low-voltage cutout.