Need help with Dometic RM2607 not turning on

Hi, I'm a new member on the RV Forum Community.

Looking for some help in getting my Dometic RM2607 fridge to work. I recently bought the RM2607 to replace an older RM2451. The person I bought it from had it working when I picked it up from him, 120V plugged in, small 12V motorcycle battery and propane tank. The fridge was working and was able to switch over to propane. I transported it to my RV in a Suburban (which means it had to be transported on its side) and left it standing upright for a week until I had time to switch the door swings.

I retrofitted the RM2607 in my 1979 Prowler, connected the 12V leads, 120V and propane. The Prowler has a separate switch labelled REFER that provides the 12V. As soon as I press the ON button on the RM2607, the Prowler's panel blinks a red ALERT. I checked the 12V leads feeding the fridge with a digital multimeter and found out that they read 17V instead of 12V( this DC voltage comes from the power converter in the Prowler). I put the meter probes on the 12V connector on the bottom left of the back of the fridge and they also read 17V there. Upon pressing the fridge's button to ON, the voltage on the probes drops to 4.36V and the lights on the fridge's control panel do not come on at all.

I have verified the following:

Both fuses on the control board on the bottom left at the back of the fridge are good (removed from board and tested for continuity)
AC source is good (118V metered)
DC source is good (17V metered; is this too high?)
Propane line is connected and on

There are no lights or LEDS whatsoever on the front control panel;  interior fridge light does not come on either.

Has anyone seen this before? Grateful for your answers.

Thanks,

Norman

Sounds like you might need a service manual. Try searching for that.

Ironically I see a CD one on ebay for your model:

Dometic-RV-Refrigerator-Service-Manual-Models-RM2607-RM7832

https://www.ebay.com/itm/Dometic-RV-Refrigerator-Service-Manual-Models-RM2607-RM7832-/181351521262?rmvSB=true

Maybe this will help:

https://mega.nz/#!lgwV2BKa!bIdi2sdAxPNDSLir6S7WH6CaDV6DYfJMCEhbHgILn7w

Cheers,

Dan K.

Thank you both for the reference manual and service tips.

Does anyone know if the 17Vdc my power converter is providing is TOO MUCH? The nominal voltage for the fridge is 12Vdc.

Thanks for any advice on this.

Welcome to The RV Forum, Norman!

Back in 1979, DC converters were electrically dirty - before fully electronic converters became available, converters often sent unfiltered DC to the majority of circuits (lights and fan motors mostly don't care about the quality of the power) and only provided a small amount of filtered DC to a couple of circuits - charging the batteries and powering TVs or stereos, for example.

There's a very good chance the new refrigerator's circuit board is balking at the dirty power.  17 volts is the peak value of uniltered DC - it looks like a series of pulses that alternate between 0 and 18 volts 120 times per second.

If your converter is the original, try connecting the refrigerator to one of the filtered outputs.  The converter's fuseboard should indicate which ones they are.  Verify the filtered output reads 12 volts DC on your meter - there's a chance the refrigerator is already connected there and the filtering circuits in the converter have gone bad.

Many thanks for the valuable information, Lou!

I work on the trailer on weekends only since I have a regular 8 -5 job. So I can't do further testing until then. Here are more observations based on the info you just provided:

After I couldn't get the fridge to work with the 17V connected (and after I metered the voltage and found out it was 17V), I disconnected my shoreline so the RV would run off the 12V deep cycle battery exclusively. I metered the DC voltage again, and this time it read ~11.3-ish Vdc. I metered the ~11V at both the 12V connection terminal and on the two connecting points on the lower circuit board. Upon turning the fridge's switch on I still get no lights on the display panel or inside the fridge. The voltage drops to 4.36Vdc on the circuit board.

I figure I'm losing the ~1+ voltage from the battery to the actual 12V terminal on the fridge due to old wiring or some loss along the way (I haven't had time for a direct connection to the battery to ensure good. clean 12V as yet).

Do you think the ~11V is now too low? Remember I finally thought of disconnecting the power converter only after numerous attempts with the 17V connected. I had also previously pointed out that both fuses on the lower circuit board were intact. I did not remove the fuse and check for DC voltage across the fuse holder.

Do you think it is normal for the 12V voltage (~11V in my case) to drop to the observed 4.36V on the circuit board?

Thanks for your thoughts.

Norman

The voltage dropping to 4 volts when you turn on the fridge suggests you have a bad 12 volt connection somewhere between the source and the refrigerator.  A bad connection can pass voltage (11 volts) when there's no load, but chokes off the voltage when you add a load to it.

What do the trailer's inside lights do when you're on the battery?  Do they light normally or dimly?  That may help you track down where the bad connection is.

Thanks again for your answers, Lou. Much appreciated!

The 12V lights work normally (no flicker or dimming) when the converter is connected. They (understandably) dim slightly when I cut the shoreline 120V power, but no flicker whatsoever.

I will get a small 12V batttery and connect it to the fridge to ensure a pure source of 12V.

As I mentioned in one of my previous posts, the fridge's source of 12V is from the Prowler's "test panel box." There is an ON/OFF switch there labelled "REEFER" along with other LEDS that indicate water, holding tanks and battery levels. I can't verify what's going on in this box as it is inside an upper cabinet.

I have also not verified if all the sources of 12V inside the trailer are indeed at 17V and if they also all drop to ~11V when the shoreline is disconnected.

I will get a small 12V battery to do the test and also verify the voltages of the other 12V points inside the trailer.

Thanks,

Norman

Success!

I bought a new 200 CCA 12V battery and connected it to the Dometic's 12V terminals. I plugged in the 120V cord and pressed the ON button. The fridge lights came on right away and I could hear the piezo-electric trying to fire.

So the problem was isolated to a dirty source of 12V.

Thanks to all who provided suggestions and documentation, in particular to Lou for helping me pinpoint this issue to dirty 12V.

Thank you all,

Norman

Thanks for reporting back your happy outcome!
) ) ) ) )