Scamp Fridge Trouble

[Thee Jimbo]

Originally Posted by Paul O.

Well, there is more to it than I thought. That schematic helps. There are two different resistors inside the element, so the connection matters a lot. If you swapped the brown and red, you may have burnt out the 12 volt side with the 110 volts.

There is a little bit of glass insulation that you have to pull out carefully and replace later. Each side of the heating element should have continuity, tested with a meter. Then there is that 10 Ampere fuse in the grey wire line. Make sure it is good.

I appreciate all the guidance, I have traced the 12V collections from battery all the way to the 2nd connection to the terminal strip (after the switch) have tested the switch etc. There is a small voltage drop but all looks good. I have started pulling out the insulation, and its really packed in there. Does this metal box come of easily?

And when I test the element, am I just testing for continuity??? or a certain resistance?? or. . . ???

BTW 120 was never hooked to the 12V element, just reversed polarity on 12V supply.

[Thee Jimbo]

OK, heres the latest. I have a 95 watt element, which means I should see 1.515 ��٠at 12V and at 127.36٠at 110V. When I check the 12V side it is almost straight on, and when I check the 110 Side it is actually a little low (but cools great at 120V).

So it appears my element works good.

BTW I connected it directly to the battery and it gets really hot really quick.

Maybe Im just not getting enough 12 V current to the unit.

thoughts??

[Iowa Dave]

Sorry to hear you are having refrigerator problems. Hope you get it figured out soon. On block ice, ain't it the truth as the old cartoon line goes. My attitude and outlook for the next few hours improve remarkably when I happen on to a vendor who has block ice, that's hard like a rock, at
a reasonable price. All too rare but great to luck on to. Wouldn't it be great if someone created a cyber block ice / good deal on bag ice national directory. Now that would be a cool application for the I phone I could use.
Dave

[Paul O.]

I am looking at this again after two days away. The next failed component could be what they call switch on the schematic in your post #19. At this point I would try to see if there is voltage on the switch terminals, on the heating element side, after you try to run the fridge. Hopefully you can gain access to the terminals.

It all does look pretty well aged and rusty in the photo.

[Thee Jimbo]

Originally Posted by Paul O.

I am looking at this again after two days away. The next failed component could be what they call switch on the schematic in your post #19. At this point I would try to see if there is voltage on the switch terminals, on the heating element side, after you try to run the fridge. Hopefully you can gain access to the terminals.

It all does look pretty well aged and rusty in the photo.

Good Morning Paul, the rust is just superficial. It "does" cool, just not efficiently. I traced the circuit and all connections are good. There is a minor current drop in the 12 V line as you work your way through the circuit. But nothing Major. that being said, I removed the element, and it does get hot.

It is a 95 Watt element and my Ω reading should be 1.515 if I did the calculations right. I get high 1.4 something so it seems ok.

Put it back together (minus the insulation) and 120V gets me down to 40 degrees, am testing the 12V now (with a charger hooked to my battery) to see what the 12V pulls to.

The Gas gets the tube really really hot, in the back, but doesnt seem to drop the temperature much.

Perhaps I need a recirculating fan.

the seals on the front seem adequate.

Im sure testing it in the summer in my garage isnt the best, but the tubes in the freezer are icy and cold, but maybe just not cole enough to cool the rest of that tiny little box.

Ideas???

[Paul O.]

It seems the only question remaining is how well (fast) is it supposed to cool. Most people around here, including us, turn the fridge on the day before we leave on our trip, because it is so slow to cool. We also put already frozen stuff in the freezer compartment. The absorption cooling cycle is much slower than the household fridge or freezer with the compressor cycle. I am not sure about its energy efficiency comparison, but it is slow.

Any other ideas? Maybe it is not as level as it should be (I doubt it). But, consider the opposite. Is it possible that the flow in the complex piping got disrupted and developed some sort of vapor lock? In which case I would tip the trailer this and that for a few minutes while it is running and see if that helps. Now you probably know as much about the beast as anybody on this forum!

My fridge is 110V AC or gas, no 12V DC mode. Maybe the 12V DC mode is only intended to be used while towing, because using gas on the road is not recommended. This has been a topic here repeatedly, the gas is supposed to be turned off at the cylinder while fueling the TV. The only time I am absolutely sure the gas must be turned off is on a vehicle ferry. The crews enforce that very strictly.

[Thee Jimbo]

The fridge is currently out of the trailer, it has been turned upside down and rocked as well. Maybe I need to repeat.

I ran it on 120 for 24 hours and got it to 40 degrees F, this morning I hooked up the battery and will see if it is still at 40 or has warmed considerably. Fingers crossed and thanks for the feedback.

More coming this evening.

[AKscamper]

Originally Posted by Mark Shaffer

Raya, There are 2 heating elements, one is a 110 volt ac element and another 12 volt dc heating element. The 12 volt element never fails, but is not very efficient for using. The 110 volt ac heating element is only powered when the refrigerator is set to ac power. The most efficient and fastest way to cool your refrigerator is the propane setting. I have seen the propane side not work on several campers also, but the main reason is dirt or spider webs inside the combustion chamber where the pilot light is burning. If the refrigerator runs on either 12 volt or propane, the problem has always been the 110 ac heating element. The metal cylinder pictured above is where all 3 types of heating are applied to the amonia system. The propane is just a small pilot light under the cylinder, and most of the time there is an inspection cover that you can look into to ensure that the flame is lit. The heat just expands the amonia into gas like a compressor compresses freon in a standard residential refrigerator.

One other thing to look for on the rear of your refrigerator is the tubes or coils. There is a recall of certain models for leaking in the tubes where oil seeps out and runs down into the pilot light and burns your RV to the ground. The recall is mainly for double door models, but I always check mine for damage or leaks. I figure if there is a problem with one model, why not others? I deal with alot of different campers and RV's and have seen many with the sides burnt out from the refrigerator defect. Most people blamed it on traveling with the propane on, or wasp nests, when in fact it was the defective Dometic refrigerators.

Does that answer your question?

Mark

Hi Mark, I hope you’re still around on this forum. Your fridge info is very helpful. I have a Scamp with a Dometic RM 2201 3 way. It works great on AC, I don’t have DC hooked up and it won’t get cold on LP. You mention dust or cobwebs for an LP problem. I’m wondering what’s the best way to clean things out if that’s my problem? And if it’s not, any other ideas for an LP problem? Thanks in advance.