Dometic RM2652 5A fuse keeps blowing

[itsjustjer]

I have an older RM2652 (product number: 921 14 40-02 if that helps). It will run on gas just fine, but when I try to run it on AC the 5A fuse that leads to the AC heating element will blow. I’m trying to determine if I need to replace the circuit board or the heating element. Or possibly something else? If the parts weren’t so costly I’d just shotgun it and replace both components, but I need to be deliberate about what I replace with this. Thanks in advance for any help!

[itsjustjer]

enblethen wrote:
No, you would not need to do anything else except replace element. It is just a double check that is the problem.

Ok got it. I’ll double check it before I buy anything or start tearing stuff apart. Thanks for your help!

[enblethen]

No, you would not need to do anything else except replace element. It is just a double check that is the problem.

[itsjustjer]

enblethen wrote:
Yes, but check with Ohm meter for continuity between ground and the leads. Commonly, the element goes to ground where it enters the stack.

I’ll check that out to see if it is shorted to ground. What would that mean if it is? Would I need to do something else if it is?

[enblethen]

Yes, but check with Ohm meter for continuity between ground and the leads. Commonly, the element goes to ground where it enters the stack.

[itsjustjer]

I unplugged the heating element and turned the fridge back on. The fuse did not blow and the volt meter showed 123v going to the fuse and the connection point for the heating element. That would mean the heating element is the problem, right?

[enblethen]

Yes, if it was in cord or input area of circuit board before the fuse, it would trip the breaker.
Yes, to BFL13, also

[BFL13]

enblethen wrote:
Did you use an Ohm meter to check element to ground?
Relay on circuit board could be problem. You could pull circuit board. If relay is the issue there will be burnt area on back of board.
Resistance is not that far off. That much variation could be in different meters.
If you change out circuit board, I recommend a Dinosaur Electronics version.
Problem is between the 120 volt fuse and the element not in cord.

Is that because if it were the cord it would pop the breaker for the receptacle the fridge is plugged into?

[enblethen]

Did you use an Ohm meter to check element to ground?
Relay on circuit board could be problem. You could pull circuit board. If relay is the issue there will be burnt area on back of board.
Resistance is not that far off. That much variation could be in different meters.
If you change out circuit board, I recommend a Dinosaur Electronics version.
Problem is between the 120 volt fuse and the element not in cord.

[Old-Biscuit]

5A Fuse is for the 120VAC circuit on the circcuit bard and for the heater eleent

Unplyg the element leads ....replace the 5A fuse and turn fridge on
Fuse Blows.....circuit board
Fuse doesn't blow........element (plug the leads back onto circuit board and see if the fuse blows)

[MEXICOWANDERER]

If unplugging the heating element stops the short...no?

Then unplug the refrigerator then unplug the harness to the heating element

[stickdog]

itsjustjer wrote:
Just to update: I checked the heating element and it’s 37.4 ohms. The spec in the manual says 44. Am I likely too far out of spec?

I would say so.

[itsjustjer]

Just to update: I checked the heating element and it’s 37.4 ohms. The spec in the manual says 44. Am I likely too far out of spec?

[BFL13]

Unplug the 120v input cord from the circuit board and check that cord. It may be shorted somewhere. Check where the green wire from it is screwed to the chassis by the plug to the board.

Un-do the 120v element from the board and check that. You can run the element directly using a made-up adapter by-passing the board to see if it heats up ok. All the board does is provide a thermostat to control the heat element to be on and off.