Bighorn Refrig and Stove Lights/Fan Wiring FYI

[wdk450]

Gang:
This is a problem which might be specific to Bighorns of my manufacture era, and maybe even to just my custom-modified unit (I retrofitted fluorescent lights over the stove and prep area). But to start with the important point to know is that the wiring to the stove lights/fan is an extension of the refrigerator 12 volt circuit, tapped at the connection terminal for the refrigerator in the outside access panel; and when ANY component in this circuit shorts IT NORMALLY BLOWS THE 12 VOLT FUSE FOR THE REFRIGERATOR, AND THE REFRIGERATOR QUITS (without you in the truck knowing it). This problem has been VERY, VERY intermittent for me (it just happened yesterday near the end of a 4000 mile trip - the last time it happened was last August). I have isolated the problem to the circuitry beyond the refrigerator, but as yet cannot find anything specific causing it.

My cure, put in place last August, was to put a small, 5 amp fuse inline with the stove electrical circuit at the refrigerator terminal strip. The fuse on the entire refrigerator circuit is 15 amps. Yesterday, when I arrived at my destination, my stove lights and fan would not work but MY REFRIGERATOR KEPT WORKING!!! Sure enough my extra inline fuse blew, but prevented the main refrigerator circuit fuse from blowing and warming up the food.
I replaced the 5 amp fuse and everything works OK again.

 

[Ray LeTourneau]

Thanks for the heads up Bill. does your fridge have an ice maker? If so, check the heating circuitry for the water tubing and solenoid. There is a wire that runs inside the fill line from the solenoid up and a heat tape wrapped around the solenoid as well.

 

[wdk450]

Ray:
Well the auxiliary fuse blew again on yesterday's run. I will now start trying to isolate the problem by disconnecting the 3 stove devices (over range light, prep area light and fan) one by one and see if the fuse blowing stops. So far resistance measurements when stopped and the fuse is blown has revealed nothing, along with visual inspections of the wiring and devices. The problem is my frequent travelling is over for a while, so no stress test for the disconnects.
The icemaker issue should be moot. The icemaker runs on 120 VAC only, and this is a 12 VDC circuit problem.

The great thing is that my refrigerator kept working down the road in the 100 degree heat yesterday. The stove area stuff not working is just a nuisance, not a disaster.

 

[wdk450]

Ray:
Well the auxiliary fuse blew again on yesterday's run. I will now start trying to isolate the problem by disconnecting the 3 stove devices (over range light, prep area light and fan) one by one and see if the fuse blowing stops. So far resistance measurements when stopped and the fuse is blown has revealed nothing, along with visual inspections of the wiring and devices. The problem is my frequent travelling is over for a while, so no stress test for the disconnects.
The icemaker issue should be moot. The icemaker runs on 120 VAC only, and this is a 12 VDC circuit problem.

The great thing is that my refrigerator kept working down the road in the 100 degree heat yesterday. The stove area stuff not working is just a nuisance, not a disaster.

Well, I kept blowing my add-on fuse intermittently, and I FINALLY found the problem!!! The wire pair going from the refrigerator terminal strip to the over-the stovetop lights took a streched, zig-zag, route. It was firs pulled toward the trailer front end of the outside access panel, was attached to a screwed cable tie, then did a sharp 180 degree turn at that point to head back and up in the refrigerator enclosure to go to where it penetrates the enclosure's wall to get to the stovetop/prep counter lights. Well, the installer pulled the wire pair sharply AROUND the cable tie screw, instead of just letting the plastic cable tie hold the wire. And, of course, the inside wire nearest the screw body was the 12 volt hot wire, which wore through to the screw body, which was screwed through the grounded sheet metal of the rear of the refrigerator. I did find burn marks on the wire on this one.
I pulled off the whole cable tie setup to give the wire pair some badly needed slack, repaired the damaged part of the 12 volt positive wire, and I think all is now well, but I will leave my extra fuse in.
Again, the biggest headache of this whole saga was having the main 12 volt fuse to my refrigerator blow intermittently, repeatedly, and finding my refrigerator shut down during a trip (before I added the 2nd fuse in the circuit).