Need help with Dometic 2652 fridge

[wrgrs50s]

As long as I can remember I've had the issue of my fridge automatically switching to propane, even though 110v was present. So, according to the Dometic manual if I have 110v present at the circuit board, from the plug, but not transferring power over to the heater rod with the auto button in the on position, it is likely the lower circuit board is bad.

So far...........

I tested the outlet plug....is good and hot and neutral are wired correctly
Tested the end of the cord to the circuit board....good
Tested heater rod...showing 44 ohms which is in spec
Tested continuity on the ground....good
Tested all of the 12v side.... all good...13vplus is present on all connections
Tested fuses 12v and 110v side, in and out of the fuse holders

I concluded that the circuit board had to be bad and ordered a new dinosaur board, I installed it today and same problem exist. I'm flabbergasted !!

I called and spoke with an RV Tech and he concluded that all the test I run has ruled out the obvious which is usually a receptacle issue or heater rod issue. He said I have a very unique problem that he has not run across before and that he has never received a bad circuit board from Dinosaur and especially with the exact problem from the previous board. I did try plugging the fridge into an extension cord to no avail, just to make sure I didn't have a loose wire in the receptacle or elsewhere that may be causing some sort of erratic behavior.

My thoughts now are leading me to the eyebrow circuitry. I'm wondering if the switch for propane only is somehow bad and shorted to the on position and is causing the fridge to override the auto position and go to propane every time I turn it on. I have had some erratic behavior with the on off switch not lighting up when pushed on so I pulled the eyebrow board out and sprayed both switches with contact cleaner. That did not change my problem, although it did fix the on off button to light up each time I switch it on to auto.

I'm hoping one of you guys familiar with this refrigerator operation can offer me something else to check. Any Ideas will be greatly appreciated.

 

[wdk450]

I would wonder about the eyebrow board connector and wiring. If it were me, I would start with a spray of electrical contact cleaner on the connector pins (I LOVE Caig Cramolyn DeOxIt contact spray). You might also spray the logic board end connectors of the cable. Next ohm out the interconnect wiring, wiggling it some looking for intermittents.

You have done a thorough job of checking everything out. Good luck in finding the cause of this weird problem.

 

[wrgrs50s]

I would wonder about the eyebrow board connector and wiring. If it were me, I would start with a spray of electrical contact cleaner on the connector pins (I LOVE Caig Cramolyn DeOxIt contact spray). You might also spray the logic board end connectors of the cable. Next ohm out the interconnect wiring, wiggling it some looking for intermittents.

You have done a thorough job of checking everything out. Good luck in finding the cause of this weird problem.

Thanks for the suggestions Bill, I tried each to no avail. Just for kicks with the unit off I punched the propane button on the eyebrow off and on about 10 times vigorously and then hit the auto on button and it went to electric. At that point I felt sure the propane switch/circuit board was faulty so I ordered a new eyebrow circuit board and that has resolved the issue. It was a long drawn out process finding the culprit but was a good learning experience. I just wish I could have figured this out before replacing the lower circuit board, but the test recommended in the service manual pointed there first. Oh well, I now have a spare board and a good learning experience and figure I still saved money and hassle compared to taking the unit to a shop for repair.

 

[wdk450]

Thanks for the suggestions Bill, I tried each to no avail. Just for kicks with the unit off I punched the propane button on the eyebrow off and on about 10 times vigorously and then hit the auto on button and it went to electric. At that point I felt sure the propane switch/circuit board was faulty so I ordered a new eyebrow circuit board and that has resolved the issue. It was a long drawn out process finding the culprit but was a good learning experience. I just wish I could have figured this out before replacing the lower circuit board, but the test recommended in the service manual pointed there first. Oh well, I now have a spare board and a good learning experience and figure I still saved money and hassle compared to taking the unit to a shop for repair.

You also have the benefit (I believe) of having a much better made main circuit board from Dinosaur Electronics.

Sometimes electronics troubleshooting is just using the "shotgun" approach: you keep replacing parts until the problem is fixed. Congrats on your repair!