Dometic RM2501 constantly runs the igniter? blows fuse...

[WineStream]

My '74 Overlander has a Dometic RM2501 2-way fridge (bought in 1987 as best I can gather from docs from the PO). Works fine on 120VAC.

Trying to make a really long story just long...the original RM77 fridge didn't need 12VDC for anything, so there was no circuit there. When the RM2501 (2way, not 3way) was installed, the 12VDC supply was obtained by tapping into the 12VDC that exists on the wall next to the fridge which is for the TV antenna amp. and std. round 12VDC outlet. I was trying to verify gas operation (mind you I've owned this trailer for about 5 weeks now) and couldn't get squat. Some helpful local airforums members traced this to the lack of 12VDC supply to hit the igniter (the 2501 has an electric igniter and automatic re-light). OK, great. Problem #1 solved. However, now the igniter is snapping, no flame. Turned out the nozzle was clogged. Problem #2 solved. So I go into the AS, turn the fridge knob to gas and even before I touch the button to "light" the fridge, it's sparking away. The instructions say to hold the button until the light on the panel goes off. Well, it never goes of, it just blinks with each spark. Good news is that the fridge did indeed light and had a nice blue flame. However, it just perpetually sparks, even when lit. I thought maybe this is the auto re-light feature??? Well, after letting it run for about 15 minutes, I was closing panels on the outside and I noticed the snapping stopped...and so had the flame. Fridge to temp? Nope...12VDC circuit blown at the fuse panel. I guess I know now why the PO had the 12VDC to the fridge disconnected in the first place. But, the question is: should this fridge be constantly sparking? If not, does this indicate a stuck igniter switch? Is it a bad thermocouple? Although you'd think if that were the case that it wouldn't light at all since the t-couple would force the stop of the gas flow. If the igniter constantly popping is the right thing to be happening then do I just need to wire it dedicated to the battery w/ its own 20A fuse? The owners manual states that the 2501 should have a dedicated 12VDC circuit w/ 20A fuse, but it does not differentiate between the 2way and 3way models and my assumption was that only the 3way would need a dedicated 12VDC line.

Please help! We're hoping to hit the road on Wed. for CBR and we'd like the fridge to work since there's limited elec. available.

[HowieE]

The spark should go off as soon as the flame is lite. The flame grounds out the spark and will not let the igniter recharge to the point of discharge. If you are getting a spark after the flame it sound like the spark is grounding to something other than the burner. Try turning the gas off and lighting the ref. while watching the spark to see just where it is ground to.

As for the fuse blowing. Is there any chance the 12 volts was hooked up with reverse polarity? This would not effect the igniter but would effect the control board operation.

What size fuse and what else is on that fuse besides the TV amp.

[Mike Leary]

Some hack installed it; we switched over years ago and have had problem zero.

[DEITZ645]

Jason and Andrea,
Sometimes the igniter in our '87 is a little cantankerous, but it is the opposite of yours. We get no spark. What usually rectifies the situation is to disconnect the slip connectors and sand the connectors a little to get fresh metal.

You are correct though, once the refrigerator flame is lit is should stop sparking. Try refreshing ALL the slip connector connections and see what happens.

As an interim fix, you might be able to disconnect the piezo electric igniter and light it by hand. If the refrigerator goes out the lack of heat on the thermocouple should shut down the gas solenoid.

If you can get it lit and limp to CBR, I am sure they will descend on your refrigerator problem and have it diagnosed and fixed in no time.

Have fun at the CBR!

[WineStream]

maybe the weather at CBR will be more condusive to fixing a problem than it is here in northern Ohio right now! It's windy and about 43 outside. NOT the time that I enjoy standing next to the trailer trying to get the @#&^% fridge to work. Not to mention the water leaks I found when I hooked up to city water this weekend...I think we'll be at CBR with more of an aluminum tent than an RV.

[WineStream]

Originally Posted by Mike Leary

Some hack installed it; we switched over years ago and have had problem zero.

switched over? meaning what...to a 120VAC only fridge? I've been contemplating that. We need to see how many times we do these situations like CBR where we are on little or no electricity. Then again, we're already re-planning our menu to include things that do not need refrigeration banking on the fact that this problem won't be fixed in time for CBR

[DEITZ645]

Originally Posted by atobols

maybe the weather at CBR will be more condusive to fixing a problem than it is here in northern Ohio right now! It's windy and about 43 outside. NOT the time that I enjoy standing next to the trailer trying to get the @#&^% fridge to work. Not to mention the water leaks I found when I hooked up to city water this weekend...I think we'll be at CBR with more of an aluminum tent than an RV.

Jason,
Ahhh...the joys of Airstreaming

I know how you feel. I spent the first weekend of last season rebuilding the water heater in our '87 in the cold rain. New circuit board, gas solenoid valve, burner tube assembly, E.C.O, T-Stat, and igniter. My wife was sick of sitting in the bathroom and listeing to me..."OK turn the water heater on...OK, now turn it off."

Where do you have water leaks in the fresh water system???

[Mike Leary]

Originally Posted by atobols

switched over? meaning what...to a 120VAC only fridge? I've been contemplating that.

Nope, a Dometic "Classic", either a 2620 or 2820, operates on propane or 120 volt. Switches automatically. Not sure if you've got the same size as our mo/ho; but worth a check. Dometic.com

[Frank's Trailer Works]

Jason, you can always pretend you still have a tent and use coolers. Another option is to put a block of ice in the fridge. You make it to CBR and someone there will scratch their head enough to figure it out. Do not fret, someone will help fill any of your needs there. I hooked up my water today and found water pouring out the bottom. Nothing like getting ready to go out for the first time. Looking forward to seeing you Thursday. Frank

[WineStream]

Well, the fridge is vindicated from the fuse blowing issue. I completely disconnected the 12V circuit of the fridge and connected it to a battery directly (with a 20A fuse in-line) and it didn't blow the fuse. However, it still is doing the constant igniter snapping. There's something else in the circuit that's all of a sudden blowing the fuse, but that's a topic for another forum.

I haven't taken the advice to stand outside and see where the arc is grounding (it's late, it's windy, it's cold) so I can't answer that suggestion yet. Anyone else out there with ideas? I think this fridge is old enough that it shouldn't have a circuit board controller. I hate to take it to have it serviced (would have to give my first born plus one arm, I think), but it kinda blows having a high dollar piece of hardware that doesn't work how it should and thus prevents me from having the 100% best camping experience.

[mimiandrews]

The RM2501 from our '66 Safari ran in the shop for two days on a barbeque bottle and regulator and 12 volts from a small battery charger. No way it needs 20 amps DC to run on propane. It was a 6 amp battery charger, and the meter on the charger didn't read any current at all.

The test run (following reinstallation of the rebuilt cooling unit) was quite successful. The igniter did not spark so long as there was a flame present. It sparked and re-lit the burner instantly when the flame was deliberately blown out with compressed air.

Testing is complete, so we're about to reinstall it in the Safari.

Hope this gives you some info on how it's supposed to work.

[WineStream]

Well, the electrical gremlin is found. I'll spare the details, but the gremlin was the positive circuit wire feeding the oven light. Yes, the friggin' over light circuit was my fuse blowing issue. I yanked the wires and found that the positive wire was grounding against the oven frame. There was a very small portion of the sheath rubbed away from years of traveling. I needed an excuse to toss that space-taker-upper oven anyway. So, I guess I can plug everything back up on the fridge circuit. I guess I will listen to it pop all the time at CBR and get it properly fixed later, or maybe someone at CBR will have a good idea.

[Frank's Trailer Works]

someone will have an idea. Sometimes they are good and sometimes not so good.

[HowieE]

Lets talk at CBR.

[silverleeper]

This is a tough one. Found two things on the web that might help. RVmobile had a similar problem. Dometic Service Manuel. Maybe you can find an answer with those links. Good luck!

[IggyWalker]

Originally Posted by atobols

The instructions say to hold the button until the light on the panel goes off. Well, it never goes of, it just blinks with each spark. Good news is that the fridge did indeed light and had a nice blue flame.

Did you ever find out how to fix the constant sparking? We are having the same problem with our Dometic RM2600. It will light properly then after a few minutes the ignitor will start sparking even though the flame is lit.

[HowieE]

Originally Posted by IggyWalker

Did you ever find out how to fix the constant sparking? We are having the same problem with our Dometic RM2600. It will light properly then after a few minutes the ignitor will start sparking even though the flame is lit.

The flame grounds out the spark. If you are have sparking while the flame is lite check and watch the spark. If it is traveling to the burner outside the flame, bypassing the flame, turn the ref. off and try moving the spark electrode so it will spark go through the flame area once the flame is lite.

[WineStream]

wow, surprising to see activity here after so long. Actually, no, the problem has not been solved. I still have the same issue. I have tried moving the position of the igniter electrode closer & farther from the flame area...no luck. Still spark, spark, spark even with the flame going. At this point I have given up. There's an RV service / dealer (not Airstream, but doesn't matter when it comes to the fridge) about 20 min. away. I talked to them about it and they said they could work on it. I just need to stop camping long enough + find the time to make an appt. and haul the AS there.

[IggyWalker]

It seems to be a rare problem. I found your post after a lot of searching. Ours has worked well on gas today, but still did the sparking thing occasionaly, when there was no breeze at all. It is very quirky in performance, even on 120...

[WineStream]

Just in case anyone is still subscribed to this thread...

I got the problem fixed, sorta. Due to some planned boondocking in the near future, we wanted the gas function of the fridge to work, so I took it to the local RV dealer / service provider. He diagnosed the issue as a bad igniter card but due to the age of the fridge + where the card is located (required fridge to be completely removed to access the card at the bottom, FRONT) he said that IF the card was available, I was looking at min $200. He came up with an alternative after talking to Dometic, though. I don't understand it all, but once the fridge is fired on gas, it is possible to disconnect the 12V supply and it will continue running so long as the flame doesn't blow out. Therefore, the serviceman installed a little toggle switch on the side of the cabinets in the kitchen where I can manually turn off the igniter. So far, it works great. Once it's lit and running, I turn of the toggle.