DM2652 Not Working on AC, Works on Gas

[nelsonatc]

New to me 2010 Roo 183. Fridge was working on gas when I bought it, but when I got home and plugged in, it wouldn't work on AC, switched right to gas. Runs great on gas.

I obtained all the appropriate manuals for operation and trouble shooting, here is what I did:

Checked both 3a and 5a fuses - Good
Checked resistance of heating element - 44ohms - Good
Checked AC power at plug - Good
Checked AC to board @ J5 - Good
Checked AC power to fuse with fuse in place (both ends) - good
Checked AC power to J8(power to heating element) - NO POWER

It appears that the board is not switching to AC, and may be malfunctioning.

Before I throw for a new board, am I missing anything?

[Bama Rambler]

It sure sounds like the board isn't seeing the 120 volts so it immediately switches to gas.

Have you made sure that the button on the front is set to Auto? I'm sure you have, but some times the simple things are easy to miss.

[nelsonatc]

I have been known as one to look too deep and not see the obvious, but in this case, I have the buttons set properly.

[Bama Rambler]

Since you've made sure that you have 120 volts to the board and that the fuses are good then it's certainly looking like the board is bad.

You did check for power between J5 & J6 for incoming power, and not J5 and an external neutral? Just making sure you don't have a open neutral problem.

[nelsonatc]

There is something I haven’t done yet. I did use an ext. neutral versus the neutral on the board. Let me try that this evening, and I’ll post back

[nelsonatc]

Power between J5 and ground- yes
Power between J5 & J6 - no.

Checked ground to board - Good

[Bama Rambler]

According to the service manual J5 is 120 volt hot and J6 is 120 volt neutral. There's a separate chassis ground that's the green wire.

Try a jumper wire from the known good neutral to J6 and see if you have power between J7 & J8.

[wa5tku]

If you have a clip on amp meter measure the current on the one of the AC heater leads. That will tell you if you have AC power to the heating element. If memory serves me correctly the current should be about 2.6 amps but check the service manual for the correct value.

[DouglasReid]

If I were you I would give Dinosaur Electronics a call:

Dinosaur Electronics Home. High quality circuit boards for RV appliances.

Their customer service is excellent and I am certain they will help talk you through the troubleshooting of your board.

IF the board is bad they sell a replacement board that is less expensive and better built than the factory board.

You will be well and truly pleased with them.

PS, consider an adjustable thermister from them as well. It will help you regulate yoru reefer temp much better thant he factory setup.

NO I dont own stock in them, I have just had EXCELLENT results with their products in the past.

[nelsonatc]

After exhausting most of the diagnostics, I pulled the trigger on a new board yesterday. Bought the Dino replacement. Their board has an adjustable thermister built in, so it will make for a nice upgrade.

Thanks to everyone for the tips. Will post back on the results of the board swap

[nelsonatc]

Board swap was successful. Fridge is back up and running on AC.

[Bama Rambler]

Glad that worked out. Thanks for coming back and letting us know that it worked..