76 Boler Electrical and Fridge Mysteries

[IslandBlue]

Hello everyone!

Apologies for not creating a new thread on this (I'm still figuring out how to use this mobile app).

We have just landed our very first RV - a 1976 Boler!! She's a diamond in the rough but seeing what is possible through some of the posts on this forum have us very excited at her potential!


Some mysteries are baffling us and I'm hoping someone can help.

Mystery 1:
Ours did not come with a battery and no inverter. Under the sink there are some wires that are cut! Not sure why they are cut...is it possible they are the wires one would connect to the battery to run the 12V lights and fridge (in 12V mode?). Perhaps a previous owner had the battery installed under the sink? (Have been wondering how the battery would connect to everything)






Mystery 2:
The 110 Shore power works as I plugged a night light into the 110v outlets and tested them all...but I'm not sure if the fridge is working or not. I followed the instructions (set to 110v...turn thermostat to 4...)...but it doesn't seem to be doing anything (no audible him or anything) or getting cold. Kaput perhaps?

Any help would be SO appreciated! Can post pic of fridge settings if that helps.

Richard

[Bob Miller]

Welcome to the group.

Here's a bit of info and suggestions for your new friend.
Depending on the refrigerator installed it may run on 120 VAC, LP gas or 12 VDC or all three. But, if is an original RV type refrigerator it is an absorption type and uses heat to cool (? Yep) and should not make any noise at all. It may take overnight to really cool down.

Wiring is a bug-a-boo of many trailers. Between age and any number of previous owners, what's there for wiring may only be a guess at best and dangerous at worse(?) For that reason, because the electrical system is fairly simple, I always suggest to tear out what may be left over and start from scratch with new components and wire.

Good luck and keep asking questions.

[IslandBlue]

Sound advice - thanks for the quick reply Bob!

Richard

[RogerDat]

Make sure the trailer is level with a bubble level when using the fridge, absorption type camping refrigerators won't work if not level. They use heat on the back to make coolant flow. If there is an access panel on the outside that lets you get to the fridge back check for it getting warm when plugged in and switched to use AC power.

Typically both AC and 12 volt power the same heating element, if that element is bad both sources won't produce heat. Propane is a little tiny burner, size of the end of my thumb so even if electric element is bad, propane may still work.

The wires for trailer brake, turn, marker lights are often run in the same location as the camping 12 volt wires. Those cut wires in the picture look way too heavy for normal lights etc. More like central location for converter and/or inverter.

Converter provides 12 volt and charges battery when your plugged into campground AC power so it needs heavy wire running to battery to deliver the charge. Inverter converts battery power to 110 AC to run things like a TV or other household appliance. Inverter needs a heavy wire because it draws a lot of current.

Not the same as the smaller 10 and 12 gauge wires that go to trailer lights and 12 volt camping lights, water pump, furnace blower etc.

I would work backwards from existing 12 volt items, use some masking tape to make "flags" on the wire to label what the wire is coming from. You may find they all go to a common junction, wire or location.

E.G the 12 volt cabinet lights in my scamp run on two wires that go down behind the ensolite to the same wires that provides 12 volt on the fridge. Those two common wires lead to tongue and is "main" line for 12 volt. There are colored wires running alongside those two wires, the colored wires go to the tail lights.



Battery is typically mounted on the tongue where it can vent gasses generated when it charges. I would look for the original wiring to be running up to that location BUT my 77 scamp (Boler cousin) did not have a battery or place to put one, it only had 12 volt when plugged into the tow vehicle. The "main" 12 volt line goes to the trailer 7 pin plug, which had been cut off, camping 12 volt wires capped and a 4 pin plug wired in for the tail lights. Sigh

Work back from 12 volt lights etc. and forward from hitch plug and you can at least map out the existing wires.

[IslandBlue]

Originally Posted by RogerDat

Battery is typically mounted on the tongue where it can vent gasses generated when it charges. I would look for the original wiring to be running up to that location BUT my 77 scamp (Boler cousin) did not have a battery or place to put one, it only had 12 volt when plugged into the tow vehicle. The "main" 12 volt line goes to the trailer 7 pin plug, which had been cut off, camping 12 volt wires capped and a 4 pin plug wired in for the tail lights. Sigh

Thanks so much RogerDat - appreciate you going into such detail. While reading your comments I was pondering the absence of an inverter, as well as the lack of a battery and the last paragraph you wrote (quote above) I think filled in some blanks for me. Our boler has both the flat 4 as well as the olde 7 round connector. The previous owner said it never used it/didn't work. Oddly when installing new marker lights I noticed more of the cut heavier guage wires tucked in the cracks near the wiring for the driver side rear marker lights. Since there was never an inverter one of the previous owners cut the wires since the 7 pin no longer functioned and removed the battery. Odd.

I'll be taking your advice and working backwards as you suggest! If it's a hot mess, I'll likely end up running new wire so there is no more myster

Also I left the fridge on overnight on 110 (praying I wouldn't see flames in the driveway in the night!) and in the morning and throughout the day it was definitely "cool" inside Only had it on 4 of 10 so methinks that part at least works!

[RogerDat]

Originally Posted by IslandBlue

Also I left the fridge on overnight on 110 (praying I wouldn't see flames in the driveway in the night!) and in the morning and throughout the day it was definitely "cool" inside Only had it on 4 of 10 so methinks that part at least works!

That is really good news. Might want to pick up a cheap fridge thermometer and puts some pre-cooled water jugs or beverages in for further testing. Full the fridge works much better than empty. Compare inside temp to outside temp. Find out how much outside heat your fridge can handle and still maintain acceptable inside food temp.

Since the fridge works on the 110 volt heat source the coolant system has not failed. All three power sources are just different ways of applying heat to the correct side of the cooling circuit.

I think mine has a single electric heating element for both 110 or 12 volt. Either current will cause it to heat but on 12 volt the draw (and battery drain) is very high.

To get propane working might just be a matter of cleaning the burner, flue and pipe where propane heats it. Spiders and wasps seem to love the flue and burner can get rust clogged. That little tiny burner needs to deliver pretty much its full output up to the coils for propane option to work.

There is one other thing you might want to look at if you are dealing with an original Traveler fridge. Bracket along bottom edge of fridge that is welded to the large pipe of cooling system. My bracket had broken which allowed cooling system to drop on one side. This would leave the propane stack at an angle which would not deliver heat as well. Would not matter as much to electric heating element directly attached.

Just a theory. Don't know if it mattered or not, I fixed the bracket before testing the fridge. I am sure broken bracket and sag on that side would have prevented getting fridge properly leveled for best operation.

[RogerDat]

New Home for posts on a specific problem originally posted in Welcome New Members thread.

[IslandBlue]

Thanks Roger! 😊


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