4-door Dometic Fridge Blowing 5A fuse

[Cariley]

For the second time in a few months the 5A fuse has blown on our Dometic 4-door. Any idea what would cause it to go? Blew the fuse about 3 months ago and has been OK since and then blew again within the last few days. Of course we're at home and not in and out of the motorhome so we didn't know until today and lost items in the freezer. Any ideas what would cause it to blow?

[Mr Havercamp]

Which 5 amp fuse? Plastic 12vdc atc fuse or glass 120vac fuse?

[Cariley]

It's the little glass fuse. Both times it has blown it was working fine, refrigerator temp at 34 and then just quit. We have the Progressive power management unit so probably not a surge.

[Mr Havercamp]

Is it an RM1350?

Blowing that fuse could be a few things.

High intermittent voltage, not a surge but just high voltage as in 130+ volts. Your PI EMS cuts it off at 132 volts I believe. High voltage over time can cause that fuse to blow.

An AC heating element going bad. If its an RM 1350 it will have 2 AC elements wired in series. Pull the leads and check with ohm meter. It should read 34.3 ohms.

Lower control board issue.

[Cariley]

Thanks I'll check it.

[Cariley]

Didn't want to leave this just hanging. I haven't had a chance to get to checking the elements yets. I will update when I do.Thanks

[Cariley]

Mr. Havercamp,
Finally checked heater elements, reading was 34.8 ohms.
So that probably means they are OK? Any thing else I can check?
I appreciate your help.
Happy Independence day weekend!

[Mr Havercamp]

Originally Posted by Cariley

Mr. Havercamp,
Finally checked heater elements, reading was 34.8 ohms.
So that probably means they are OK? Any thing else I can check?
I appreciate your help.
Happy Independence day weekend!

Same to you...Happy 4th.


In your original post you mention you lost some food. I assume you had the fridge on auto and when the AC fuse blew the fridge did not switch to gas......which it should. The AC side is not really complicated.....basically just an element and a relay.

I would go to the lower board next per the service manuals and do those diagnostics. Switching parts as a diagnostic can get expensive. Maybe time for a trip to or call in the pros. If it is that board replace it with one from Dinosaur instead of the Dometic replacement.

[Cariley]

It was auto but don't usually leave the gas on at home. Thanks f or the help. Get to the dealer.