Dometic fridge

Has anyone had any experience with their Dometic fridge in 100+ degree heat? We were in AZ and it seemed to be working fine at around 100 degrees on electric. I did leave the fan on because I figured it would not stay cool enough without it. On our way home I switched it to 12V and we came in to Needles CA where it was 115 degrees. We parked the trailer and got a room because unfortunately our AC had broken on the trip. I switched the fridge to propane and made sure the pilot was lit, the fan was on, and the fridge was at max. When we left in the morning, I switched the fridge back to 12V and we headed home. When we got there the fridge was warm like it hadn't even been running for 24 hours and everything in there was bad. Maybe the 12V or propane not working properly? Or can you just forget about it in that kind of heat? Any ideas on testing? Would another fan in addition to the one provided help? I am new to this and any info would be appreciated.
Thanks.

[Bill]

Flyfisher -

First, make sure the fan is running. You should be able to hear it when you turn on the switch.

Then, make sure the fan is installed so that it blows in the right direction. To do this, remove the outside cover over the lower half of the refrig. Inside you will see a piece of dryer hose, running from the floor up into the upper half. The fan is at the bottom of this hose, screwed to the floor, with the end of the hose attached over it. The fan must blow downward, blowing air out through the screened hole in the floor. You should be able to start the fan, then put your hand under the trailer, and feel air blowing out through the floor.

Having said those easy and hopeful things, it is more likely that you are one of the unfortunates (a group that includes me, by the way) whose tow vehicle won't keep the refrigerator running on 12 volts while on the road. In my case (and as reported by several others), if I run the refrig more than a 3 or 4 hours on the 12-volt setting while I am towing, the TM battery becomes completely discharged, and the refrig quits. There is no easy solution to this. The problem is in the tow vehicle, NOT in the TM.

I'm having trouble finding the original discussion, but here was a LO-O-O-NG follow-up discussion.

http://www.trailmanorowners.com/foru...ad.php?p=18079

Finally, 100-degree-plus temps are real hard for this kind of refrigerator to deal with. The cooling mechanism in a gas absorption refrigerator is simply not as capable as the compressor-based refrig in your home. Since my TM has a Norcold unit, I no longer have a manual for the Dometic frig (gotta get another one if someone will remind me of the model number). But I seem to recall that the manual had some cautionary words in this regard.

Bill

Thanks Bill,
Yes I checked all the fan stuff and it was working as advertised. Is the charger on the TV generally not strong enough to charge its battery and the TM battery at the same time when the fridge is running? I guess I would understand that. I could not get to the link you pasted. I've had a couple RVer's tell me to forget about 12V on the fridge altogether and just use propane when traveling. Are there any safety issues with that? Also, I tried to run it on propane last night. I had already gotten the fridge down to about 35 degrees with electric. I switched it to propane and when I checked it this morning it was 50 degrees! I looked at the pilot and it was out. I did bleed out the air by lighting a stove burner before I lit the pilot, so I'm not sure why it went out. The propane tank is full. I bled the air again and relit it. I'll see what happens.

I've had a couple RVer's tell me to forget about 12V on the fridge altogether and just use propane when traveling. Are there any safety issues with that?
Yes there are safety issues with running the refrigerator on propane while traveling. I think it's against the law most places - I know it is in Washington. What about stopping to get gasoline - do you want an open flame in the area when you buy gas? The exhaust on the burner may also catch your trailer on fire when it's folded. May places it's against the law to even have your propane tank valve open when towing - even if it's not against the law in your state - it's not very prudent.

[Bill]

Originally Posted by CA_flyfisher

Thanks Bill,
Is the charger on the TV generally not strong enough to charge its battery and the TM battery at the same time when the fridge is running?

Well, technically what is happening is that the charger (alternator) in the tow vehicle is plenty strong, but the tow vehicle was wired with undersize wires. The voltage drop in the long skinny wires between the alternator (way up in front of the tow vehicle) and the refrig is so big that not enough power reaches the refrig to meet its demands. The TM battery attempts to take up the slack, and gets discharged. The solution is to run a new pair of heavy wires (+12 VDC and ground) from the alternator to the 7-pin connector on the tow vehicle's rear bumper.

By the way, a couple of our members have reported that their tow vehicle came from the dealer with the trailering fuse not installed! You should probably check this. If you have a wiring diagram for the 7-pin connector, plus a test light or voltmeter, you can check it at the connector. If you don't have these, an easy way is to hook up the TM to the tow vehicle, disconnect the TM's battery (just pull the fuse that is in the red battery wire), and see if the TM interior lights work. If yes, then the tow vehicle is supplying power to them, so the tow vehicle fuse is present.

I could not get to the link you pasted...

Oops, sorry, that's because you are a Guest of the forum, not a sponsor, so your access to the technical sections (where much of the meat of the forum is found) is limited.

Bill

[YWORRYDOG]

I found that at times, running the lights and wipers, while towing just about maxed out the output of the alternator. This is with the TM hooked up and the refrigerator, and fan on. That along with charging the TV and TM batters the voltmeter was drooping down to 12.75 or so volts. I just finished getting a Reman alternator built up to 160 amps. Everything looked good on the last trip.

Originally Posted by Freedom

I've had a couple RVer's tell me to forget about 12V on the fridge altogether and just use propane when traveling. Are there any safety issues with that?
Yes there are safety issues with running the refrigerator on propane while traveling. I think it's against the law most places - I know it is in Washington. What about stopping to get gasoline - do you want an open flame in the area when you buy gas? The exhaust on the burner may also catch your trailer on fire when it's folded. May places it's against the law to even have your propane tank valve open when towing - even if it's not against the law in your state - it's not very prudent.

Very good points. That's why I asked. Thanks.

Couple of additional items.

All of the tunnels in the Hampton Roads area of Virginia require you to stop for inspection first and the propane tanks must be off! It has been that way since before 9/11 so I think it is more of an issue of propane building up in the tunnels and an explosion risk than a reaction to terrorist threats.

After our first 12 hour leg towards Co Springs with both the fan and the refridg running on DC (and I have two type 75 batteries!) I noted upon arrival that the fan was no longer running and my electric tongue jack confirmed that my batteries were dead. The second night after only 9 hours the fan was still working but the battery was close to spent. Sometime that night, my main battery fuse burned out and after replacing the fuse we chose to run the fan only on dc and the fridge on propane. It worked fine, so we did that also for the 4th day of our 2000 mile trek to Colorado Springs.

While at the Jubilee I found out from some other TM owners that the Chevy Trailblazer/GMC Envoy/Oldsmobile Bravado ships from the factory with the wire that leads to the charging pin on the Bargman disconnected. If you open the hood and remove the cover of the fuse box in the upper right hand corner and look at the bundle of wires that feed into the box you will see a red wire with a metal loop on the end, bent back along the bundle and held in place with a plastic clip. This wire can be slipped over the first post in the fuse box and secured with a nut and now you will charge the trailer from the TV! It worked like a charm all the way home and I ran on DC the whole 2000 miles back. No one had a good explanation why the factory ships the vehicles with this wire not attached. I was also told the vehicles feature an anti-rundown feature that electronically disconnects the TV battery from the Bargman when the ignition is turned off so you can not run down the TV battery while stopped for a bite to eat. I didn't test it for any longer than about 10 minutes but there was no hesitation on restarting the TV so I am feeling more confident about this feature. It would be a relief not to have to unplug the trailer every time I stop for gas and a rest room! I got a bit road weary in covering 2000 miles in 4 days and left one stop without plugging the plug back in! Luckily it was up out of the way and the plug didn't get damaged bouncing around on the pavement!

Thanks Bob Redrick and Gene for making my life easier!
Bill

Luckily it was up out of the way and the plug didn't get damaged bouncing around on the pavement!

I once ruined a cord by dragging it on the road. Now, I have a bungie cord on my electric jack post and when I unplug, I stick the plug on the bungie cord when unplugged.

genesc

good idea. I had looped it between my electric tongue jack and the cover for my porpane tanks but it easily could have worked it's way down to bounce along on the ground on that leg of the trip. Your suggestion will remove any chance of that although I like not even disconnecting it when I stop better.

Texas Camper, did Manitou Automotive mention anything about a discharge prevention feature?