The Darn Dometic RM760 Again.

Possum · 08-14-2011, 07:47 PM

OK how can a fridge that worked two weeks ago in its trailer while in a trailer decide to not work once located in the Motorhome?

It will not work on 110, 12 or propane and it did when in the original location.

I've been informed that if I took it out of the motorhome and turned it upside down for a while that it just may work again when flipped back right side up.

Does anyone give this claim credence and just how long is 'a while' in RV time?

**"007"** · 08-14-2011, 07:56 PM

If when moving it you tilted the fridge from original position the fluids have not returned to boiler tank.
If you have it installed take it for a ride over bumpy road and see if everything settles down.
You do get a good flame and 120 to your electric elements right, plus a good 12V for control board?

Possum · 08-14-2011, 08:08 PM

The flame is very strong and about 3/4" to 1" high and full across the burner slots. The voltage is full 110 volt but I haven't checked the 12V as it is just a straight connection to my batteries for this unit.

I will try the bumpy road thing as soon as possible. Just may head out a logging road tomorrow and see what happens; better yet may try getting to Bamfield via that road. Some on here have to know that road?

Kurmudgeon · 08-15-2011, 12:10 AM

Quote:

Originally Posted by "007"

You do get a good flame and 120 to your electric elements right, plus a good 12V for control board?

There is no control board in an RM760. It will work just fine without a 12V connection.

Did you actually see it work in its previous installation? Or are you taking someone's word for it?

JP

**RV Wizard** · 08-15-2011, 01:52 AM

A crystallized cooling unit can be intermittent. If the Sodium Chromate in the cooling unit has been over heated (caused by un-level operation for long periods of time) it will crystallize and the flakes will restrict the flow of the ammonia used as the coolant. A flake can be moved out of the way of a port but once crystallized it will not dissolve and will eventually restrict the system again.

**"007"** · 08-15-2011, 06:06 AM

This is what we are talking about, your right it has no control board.

Possum · 08-15-2011, 12:22 PM

Quote:

Originally Posted by 007";931031]This is [B][URL="http://gasrefrigeration.net/dom_techdata/24_77SM.PDF

what we are talking[/URL][/B] about, your right it has no control board.

If the RM76 transposes to the RM 760 then the manual is for my unit. I have printed the manual and will use it.

Will the inverted operation actually get the thing working because I will be taking the unit on a ride today on a local logging road to see if it helps get the fridge going.

Is this run done with the propane turned on and lit?

Kurmudgeon · 08-15-2011, 11:59 PM

Quote:

Originally Posted by Possum

If the RM76 transposes to the RM 760 then the manual is for my unit. I have printed the manual and will use it.

The RM76 is an older version of the RM760. I doubt there is much difference.

JP

**RV Wizard** · 08-16-2011, 02:40 AM

It will not matter if the unit is on or not. The system is operated by a gravity flow and if it has a restriction the object is to get that restriction past or through where the normal flow of refrigerant needs to travel. It is also not a guarantee that it will work at all if the flaked up condition is bad enough.

Possum · 08-16-2011, 02:32 PM

tried the 'bumpy logging road' trick last night but alas nothing happened. I will now do the invert the unit trick but still have no idea how long to leave it inverted. Any guesses?

The unit is spotlessly clean and it will be a shame if I screwed it up moving it from source to my back yard.

I found a site that sells the cooling units separate from the fridge. Is this an easy repair? I'd hate to spend $400.00 for the cooling apparatus and then screw that up too.

A somewhat discouraged Possum.

Sammie · 08-16-2011, 05:24 PM

Possum, If you end up replacing the cooling unit, let me recommend these guys RV Cooling Unit Warehouse Ask for David Force and he will help you any way he can. The cooling unit is not that difficult to change out yourself. I did mine on my Norcold 1200 and I must say after never doing one before it ended up being a great project and I saved some $$$$ in labor. Just follow the instructions they send with the unit and you will do fine. Here's a video I made of my installation. Hope it helps!

Sammie

Norcold 1200 to Amish Cooling Unit Conversion.mpg - YouTube

Possum · 08-30-2011, 03:49 PM

Thanks for the help and suggestions. I am picking up an RM2620 next Sunday 04/09/11 and it has a guarantee of working that comes with it. It is the size that Dometic calls a replacement for the RM760.

Anyone want to pick up a free RM760 in the middle of nowhere Vancouver Island.

Possum · 09-06-2011, 01:46 AM

Quote:

Originally Posted by Kurmudgeon

There is no control board in an RM760. It will work just fine without a 12V connection.

Did you actually see it work in its previous installation? Or are you taking someone's word for it?

JP

I hooked it up and watched it cool off and then ran it overnight on propane and it stayed really cold.

Moot point though as I got a super deal on a RM2607 (was supposed to be a 2620) and it is now installed and working great. Just in time for a week or so of goofing off before the season ends.

Will try again to get the RM760 going and maybe recoop my costs on the 2607.