I AM embarrassed.

This may sound like a rant but honestly, I'd be nervous bringing this fridge to an RV shop for repairs.  I've spoken to so many different people/shops/Dometic about it and I've searched for others with the same fridge/symptoms who successfully repaired it at a reasonable cost.  They don't exist.  Yes, a few guys have fixed the Dometic RM-8501 by throwing $500-$800 in parts at it but that's not what I consider reasonable.

 This is really an odd duck fridge that companies like Forest River/Airstream quit using fairly shortly after they began using them here in the US.  I suspect it was a thorn in Dometic's butt but there is no excuse for the lack of support they've given over the years on the RM-8501.  Most owners just gave up and bought a different fridges altogether.  I won't purposely buy a new Dometic fridge after this.  After so many years in business, you'd think RV fridge manufacturers could get it right and make reliable 3 way fridges but they are not and never have been.  I've owned about 8 different RV's from travel trailers to Mercedes Sprinter RV's and all of them have had fridge issues at some point in time whether they were Dometic or Norcold.  Do they purposely build garbage?  I think so...planned obsolescence.

I'm the guy, mentioned above, that found weak/bad electrolytic capacitors on the main control board of the Dometic 8501 three way fridge.  The main control board is on the top front of the fridge behind your buttons that turn it on and change modes.  Two of the three capacitors tested bad.  I was hoping that by changing these I'd get my igniter to come back to life but unfortunately I had no return of ignition.  The caps now test properly after changing them.  I've had luck repairing residential refrigerator motherboards by doing this but no luck this time around on the Dometic.  I'm extremely apprehensive about gambling $200+ on a 241278930 Burner Control Module because I have read posts where people replaced them and still had no return of ignition.

The service manual says to test two wires (pin 6 & 7) going from the main control board to the Burner Control Module (gray little box attached to the back of your fridge accessible from the vent hatch) to see if you have 1.5V powering the module.  When I start the fridge, I do have needed 1.5V but only briefly for about 5 seconds at which time the voltage drops off.  No voltage ever makes it to the electric gas (turn on) valve and no igniter clicking occurs.

 I read somewhere that if any change in resistance are detected (by the Burner Control Module) with the igniter itself (due to it being cracked or faulty) or due to damaged wiring to the igniter, then it will not proceed further or move onto opening the gas valve.  What the manual does not indicate is whether the 1.5V to pin 6 & 7 should remain on at 1.5V indefinitely as long as the fridge is powered on.  I don't know if my voltage is suddenly dropping because it's not passing some sort of an igniter resistance test or if the Main Control Board is dropping the voltage for some reason.  I called Dometic and they will not let their techs speak to the general public for liability reasons.  So speaking through a middleman operator, I was told that the 1.5V should stay on...I still suspect this is an incorrect statement if the Burner Control Module detects a problem.  

If anyone has given up on their RM-8501 Dometic for different reasons and you have a spare 241278930 Burner Control Module or even a Main Control Board, I'd love to test it and see if it is the problem with mine.  My fridge still works great in 120Vac mode and 12vDC mode.  It's still possible that something else could be wrong on the main control board but everything lights up normally and it is sending the proper 1.5V, though briefly, to the burner control module. 

I don't like to give up on challenges and Dometic has really put the screws to their customers on this one....with the crazy high cost of replacement parts that should be relatively inexpensive, guessing isn't an option.  Aftermarket companies make inexpensive boards for most RV fridges but not this one. 

My guess is the Fault light is telling of a detected failure of the propane regulation/ignition.

Do you have the means to check your electrolytic capacitors?  Recently spoke to a fellow podder with a 177 who ordered some because 2 out of 3 electrolytic capacitors tested poorly on the upper main board.  The main board only briefly sent 1.5V to the burner control unit so that looked like a real possibility as to why his weren't firing up.  Cost for those capacitors is very reasonable, compared to a new motherboard.

And yes, poston is absolutely correct.  Don't assume you have 12v power until you know you do.  The motherboard will not run without it, ask me how I know.

Not to belabor things, and I know I'm not helping much, but being connected to shore power doesn't mean you have 12V - like if your converter has failed (like mine at the moment!)

Let's assume you've got propane because you lit your stove burners.

It's not intuitive, but you need 12V for the refrig electronics.  Is your battery good?

 

Anything I should try first?

Bill