Late 1940's GM Frigidaire Refrigerator ML-77 Starting Compressor Relay Question

FishMax05

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Current draw was 1.8A - 2.0A. I didn't have a chance to record the starting draw.
I had a feeling you were going to say that about the trim pieces.. I was going to try to make them out of metal.
 

Tundrawalker

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Glad to see all the recent activity on this thread for my very similar model GM Frigidaire. Gives me hope that I will be out of the woods soon. I have looked over most of the information and compared my hand drawn diagram to the more official ones here. As is common I had to replace the brittle wire insulation on my working fridge and now I am in a wiring harness quandry. When I plugged the firdge in after carefully trying to replace the wires under the cold box to the relay and compressor, I shorted out. My wiring up to the switch, light and thermostat seem intact and i haven't replaced it....yet. Here's the problem. The diagram shows 3 wires coming from the switch, light and thermostat in the cold box area. I have 4. In the diagram 1 wire doubles up on a terminal at the thermostat. In my situation I would guess that it is not doubling up on that thermostat terminal as I have 2 wires returning from the thermostat area of the fridge and 2 wires returing from the switch area. My guess is that the extra wire returing from the switch area which in the diagram doubled up on the thermostat after routing past the light would go to the Number 1 screw on the YT Relay (the bottom left). Now here's the kicker, I have continuity across all terminals, hence why my circuit blew when connecting to AC. Ugh. Thoughts on what to do to get this fridge cold again? First image is my new wiring, secong image was my wiring schematic before taking apart, third image was the original wiring before my new replacement.
 

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rickgburton

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When you replaced the brittle wires, did you connect the wires in the right spot on the relay? Your pictures only show me a relay with wires connected to it. If you're asking if the wires are connected correctly, I couldn't tell you without knowing what the other end is connected to. Is there a wiring diagram attached to your machine?
 

Tundrawalker

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Thank you Rick for your reply, yes to the best of my knowledge I replaced exactly as it was. I know that my wires going to the compressor are correct, Which is also verified by the multiple schematics as posted here on this site. I had 2 double lead wires coming down from the cold box to the relay. One set had thicker insulation wiring and the other was thinner. At the time i had no idea where they were going as I hadnt opened up the finish trim around the cold box yet. I think what i will do next is disconnect everything to the relay and then reattach 1 at a time and check my continuity with each wire. Does that make sense?
 
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rickgburton

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Take a few pictures of the machine and post them here. Take a pic of the back of the machine, compressor compartment and wiring, front of the machine with the door open and the cold-control.
 

FishMax05

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Holt, Missouri
Hi All, I am still working on my fridge(s). Once I have them completed I will update all with my schematic and dims of "breakers".

Rick, to answer your question, I have a buddy that is a sheet metal worked. Our plan is to make the breakers out of stainless steel. I will keep ya posted on this as it is one of my winter projects.

In other threads, I have seen folks are using Rockwool for their insulation. I was considering using R15 for mine. Thoughts?

-Fish
 

Tundrawalker

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here you go. There is no visible schematic on the back. There is a glued piece of paper but it's contents are faded.
 

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rickgburton

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There is a glued piece of paper but it's contents are faded.
LOL that's the thing I was most interested in.That looks like a YT relay. It's wired like this:
R-Early relay (2).jpg

Check your relay and see if the numbers and letters match up. This shows three wires and you said you have four wires. In this diagram the thermostat has two wires on one terminal. If you were to take the wire that goes to the light bulb, off the thermostat and connect it to 1 on the relay, nothing would change. It's still connected to the same wire only in a different spot. Except, now you have four wires instead of three.
 

Tundrawalker

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Thanks, I alluded to this previously. I am going to disconnect and reconnect one at a time and see if i can track down my issue. plus I will crimp eyelets on all the wire ends to make the screw connections easier.
 
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