Fridge fan (external for coils) questions


icarus

Moderator
After reading the bentley, as well as this thread, and rv mobiles great site(they have an extensive forum if you want to know (almost) everything about l/p fridges), I'm wondering at what temp the fan should turn on/off? (86 SYNCRO) Mine runs, but seems to cycle on and off quite quickly. The fridge maintains a temp about 35-40f below ambiant. It seems that the fan should be on more than it is, especialy when the cabin is warm. (75+f)

Icarus
 

Capt. Mike

Moderator
Since specs will be next to impossible to find -- VW bought the unit as an assembly -- that it works & cycles is probably sufficient. Dometic may be able to dig it out for your, but I doubt VW.

Since it's purpose is to reduce coil temps and facilitating the heat exchange from the heater resistance strips, it probably only comes on when they reach their highest temps and then just sufficent to avoid overheating. Although its power source appears independent of the heater strips, its location probably makes it dependent on them at their highest temps so if the fridge is working well and cycling fairly short, the thermo switch won't activate long either.
 

Flyfisher 1

New member
Well as a new Westy owner (88) I was pretty surprised to know that there WAS a fan with the fridge. No sound of a fan running. (Just the rumble of perculating ammonia) Been running mine for three years without it I guess. Have I damaged it? Or is it just not effecient as it should be. Can anybody help me? (If it is not being damaged -4 F to + 114 F operating range for last two years can i just leave it alone?)
 

Capt. Mike

Moderator
Transferred to consolidate same topic.

MitMar Junior Member Posted May 05, 2007 05:19 PM

I get a squeal sound when running on LP. It is intermittent and last about 1-4 minutes. Otherwise the fridge is great, it always starts and runs cold. Any thoughts would be great.

82 Diesel Westy
 

Capt. Mike

Moderator
Since literally the only moving part in the fridge system is the fan, it's probably a fan needing lubrication or getting close to seizing.
 

goldvan

New member
Originally posted by Capt. Mike:
Well of course you should be concerned because an electric motor, even the little ones consume power. And unless you've installed a dual battery set-up, that power is coming from your main battery.

When the fridge is OFF, the fan shouldn't be running. That yours is would indicate the fridge fan thermo switch is stuck or defective. See Bentley 97.33, track 16. I assume you are turning the fridge 3-way switch back to LP position when not running; that is the normal fridge-off setting.

On vehicles that have installed a 2nd battery, do understand that VW's original system disconnected ALL fridge power as soon as the engine stopped. Therefore they would have little incentive to arrange a system whereby high ambient temperatures wouldn't trip the fan even with the fridge off. You may find that your now continuous power to the fridge controls also provides a means for the fridge fan to power up with the fridge off. I've never experinced it with my '90, despite some baking interior temperatures so still lean towards a defective thermo switch or switch setting as I don't see an alternate power trace in my copy of the wiring diagram.
I have the same problem on my '86 Westy. It started after I replaced the cooling fan (old and gunky) with a new one from GoWesty. Any thoughts? It is killing my auxillary battery.
 

Capt. Mike

Moderator
The Westy wiring diagram 97.34h conveniently leaves out the actual fan motor. But the fan thermo switch, circuit 12, indicates the fan should run on/off via the switch ONLY on DC. Note it is not connected to the AC mode. If you look at the '80-85 diagram 97.33, you will see it shows the thermo switch and fan on the DC side, but that the wiring is actually independent of the mode switch. I presume that it is the same in the later models. This leads to the conclusion you either have a bad thermo switch -- which may have been disguised by your old fan -- or miswiring.
 

Ptellez

New member
I just bought a vanagon (90 westy US model - only 1 battery) and I am new to this forum.

My fridge fan keeps working with the engine off.

I found out that the previous owner had disconnected the 12v wire (connection inside the compartment under the driver's seat) that I believe powers the water pump, LED panel and fan.

After connecting this wire back, I noticed that the fridge immediately started making a noise (probably the fan) and keeps working even with the engine off...
I had to disconnect the wire back so that it would not drain my battery.
Does anyone know what could be the problem?
Thanks,
 

icarus

Moderator
The fridge fan WILL run with the engine off. It is designed to cool the coils on the back of the fridge. It should cycle on and off as the temp of the coils heats and cools.(this is assuming that the fridge is running. If the fridge is not running it shouldn't run) If it runs continuiosly it sounds as though it is mis-wired.

As to drawing the battery down. The fan draws about 1/2 amp and will (If cycling properly) have little effect on the battery.

Icarus

PS Try RVmobile for the switch
 

Ptellez

New member
Thanks for the tip Icarus

Looked again in RV mobile, the part was not available. Actually very few part for my fridge model number were available. .
I have the RM128B.

DO we all have the same fridge model number? or do I happen to have a rare one?

Any more ideas on where to find the switch? I also tried Go Westy, the bus depot and Camping world

Thanks!
 
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icarus

Moderator
The thermo-switch should be rather generic. All it does is trigger the fan, so it shouldn't matter if it were a different one. I would suggest calling RV Mobile and asking them to suggest a substitude. They are EXTREAMLY knowlegeable as well as helpful.

Icarus
 

Capt. Mike

Moderator
I can find no record of a Dometic RM128B. The VW's usually came with Dometic RM182B. I've sent you the Dometic RM182B service manual via email.
 

pdasilva

New member
I have the exact same problem.
Were you able to fix it?
what is the part number for the thermoswitch and how much does it cost?
 

vanis13

New member
Therma Switch Specs Dometic RM182B

Dometic RM182B Manual Pg 3 - "In order to improve the cooling performance under difficult built in situation and high ambient temperatures a 0.6W ventilator is switched on automatically when the temperature around the condenser fins is about 126deg F and switched off at 108deg F. The ventilator is connected to the 12V system.”
 

Capt. Mike

Moderator
My Ed. #2 of the service manual shows it coming on at 140°F and cutting off at 124°F. The manual is 18 pages and too long to post on our tech drawings site, but I can provide a .PDF copy to members who have a valid public profile email. Please note it is geared to professional repair & service techs. It does not add anything to the VW owners manual or this site's posts as to operations and use. I understand there is also one posted on Vanagon.Com
 
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MMR

New member
84 Westy external fridge fan keeps running

Hello - I'm experiencing the same issue. Fridge is off (switch is on LP, etc) and I come out to the van in the afternoon and the fan is running - drawing down thw battery. Only way I have found to make it stop is to take out the fuse behind the driver's seat.
What part do I need to replace? Do I need to remove the unit to get this done?

Thank you,

Martin

[Moderator's Note: Answered above! Post #27. Guideline #4. Duplicate post so will be removed next clean-up.]
 
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tvp

New member
fan problem

Same issue. My RV guy (who is great with Westfalia's) says that it's the switch. You can try replacing it (access through grill area left of stove unit) or just take out the fuse, as you do. I had it replaced and still does the same. Bit of a pain, but I don't think it draws much from battery. I pull the fuse when cool out or at night.

TVP
 

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