RM3962 Refrigerator question

Bobby A

Well-known member
The last couple months our refer has been acting funny, not cooling normally during the day and then overnight it regains its normal temp. My question is I have read about having 2 fans in the back of the refer, so I got on a ladder today and opened the top vent and looked down and I only see 1 fan ?? Its close to the top, so where is this other fan suppose to be located ?? Next, I have a suspection my problem MIGHT be the fan might of went bad, thats why all of a sedden it started acting crazy. Can fans go bad ?? Also I read about some sort of thermal limit switch that runs the fan ?? and if that brakes it won't let the fan come on ?? What does this switch look like and where is it located on the refer ?? I have been keeping an eye on the fan and it hasn't come on all day, how do I check it ?? or the limited switch to see if either needs replaced ?? Lastly, do I have to unhook the battery cables to remove or replace this 12 volt fan ?? Sorry for all the questions. I appreciate getting all answered.

Man, I been making a lot of post lately !!

Thanks in advance,
Bobby A
 

wdk450

Well-known member
Bobby:
I believe that some models of refrig have 1 fan, some have 2. If you can follow the wires from the fan, one of them (the positive - Red?) should go directly to the thermal switch. It is always safest to remove the battery cables when servicing anything on the 12 volt DC system, but the fuse for the refrig should just blow if you cause a short circuit. That being said, there are several fuses involved with the refrig 12 volt supply, and you might have a hard time finding the one that is blown. Better to avoid causing problems if in doubt.
 

cookie

Administrator
Staff member
Bobby, the thermo switch is located on the upper cooling fins on the back of the refer. It is just a small button screwed to the fin. There are two wires going to it. One is the 12 volt supply and the other goes to the fan. You can remove the two wires and jumper them together. That will make the fan come on. If it does not run properly most likely the fan needs to be replaced. They are under 10 bucks, in fact I just saw them at the computer shop for 4 bucks. Do check for 12 volts at the supply wire. That would be the one not going to the fan. If you do not have 12 volts, check all your fuses.
If the fan runs then most likely the thermo switch is bad. Many people bypass that and run the fan 24/7.
Unless you have the 1350RM you will have only one fan.

Peace
Dave
 

JohnDar

Prolifically Gabby Member
Bobby, pull off the lower outside refer vent cover. In the center of the photo, you will see a 5A fuse holder. That's the fuse for the fan. My refer (DM2862) only has one, at the top. If your's had two, they would be side by side on that mounting flange. My flange has holes and space to put a second one, if I wanted. The other location for mounting fans appears to be the center of the cabinet, as seen in the second photo I took at the plant. Not sure which model it is, though.
View attachment 15731 View attachment 15732
 

Bobby A

Well-known member
Wow, such GREAT information from you guys,

Bill- you spoke of several fuses ?? where are they ?? more than the one that John posted ??
Dave- So I can just take the 2 wires off the thermo switch and touch them together to see if the fan works ?? Is there any problems letting the fan run 24/7 like you spoke of ??
John- Thanks for the pics, I like visual, could I put another fan next to the original one to get more air flow ?? Would I have to change any wireing or a larger fuse, or just put the new fan wires with the old ones ??

Thanks guys Happy Labor Day !!
 

cookie

Administrator
Staff member
Yes Bobby, just take the 2 wires of the thermo switch and touch them together. If the fan is good it will run. This is low voltage, so no worries of a shock. There are spade connectors on the ends of the wires. You can take a flat automotive type fuse, say 15 amp, and just plug those two wires onto the fuse. That will be your jumper. If you do this be sure to tape it up to prevent any short to ground.
These fans will run a long time continuously. They are cheap enough to replace when they die.

Peace
Dave
 

Bobby A

Well-known member
Yes Bobby, just take the 2 wires of the thermo switch and touch them together. If the fan is good it will run. This is low voltage, so no worries of a shock. There are spade connectors on the ends of the wires. You can take a flat automotive type fuse, say 15 amp, and just plug those two wires onto the fuse. That will be your jumper. If you do this be sure to tape it up to prevent any short to ground.
These fans will run a long time continuously. They are cheap enough to replace when they die.

Peace
Dave

Thank you Dave, I appreciate the info very much.
 

cookie

Administrator
Staff member
One more thing Bobby. There is some really hot tubing back there. Be careful, you will blister.

Peace
Dave
 

Bobby A

Well-known member
One more thing Bobby. There is some really hot tubing back there. Be careful, you will blister.

Peace
Dave

10-4 Dave, thanks for the tip, I will first inspect the fuse that JohnDar posted a pic of, maybe somehow that fuse blown. I guess I should turn off the fridg from the inside first before inspecting that ?? Than I will procede to do as you/others have mentioned. I will post back with my findings.

Thanks again,
 

JohnDar

Prolifically Gabby Member
Bobby, I thought about it last night after I posted. The other two fuses (3A and 5A) are located inside the black module housing in the photo. I think they have more to do with the display circuitry and protect the module board. The cover even shows their location.

View attachment 15764
 

Bobby A

Well-known member
UPDATE,

Well, it turned out to be the thermo switch and a blown 3 amp fuse, I probably touched the fins when removing the wires on the thermo switch and blew the 3 amp fuse. Thanks to my neighbor (because I know nothing about a multi meter) we got it fixed using the by-pass method that Dave spoke of, the only thing is the wife doesn't like hearing the fan run all the time. I don't remember hearing the fan like I do now. John-- I don't have an in line fuse like your pic shows, but I do have a gray cover with fuses inside, thats where the 3 amp blown fuse was located, all is good for now, I may go get a new thermo switch and another fan tomorrow to keep on hand.

I had another mis hap read my thread in plumbing for that update.
Thanks everyone.
Peace,
Bobby A
 

Bobby A

Well-known member
thermo switch removal question

This is a question in regards to a previous thread I created a few weeks back.

I removed the thermo switch (because it was not working) and used the direct fuse to fan method that Dave suggested in my earlier thread so the fan runs 24/7. My question is, I've noticed ever since I have the fan on 24/7 I do not get any frost build up on the fins inside the back of the fridg. Not that I'm complaining about this, I just want to make sure this is normal when doing this ?? Model # RM 3962, with this method the temp remains at 40 degrees on #3 setting hear in MI. I'm sure that number will change and setting will have to be adjusted as we travel south to Florida in a week or so.

Thanks very much,
Bobby A
 
Top