About 2 months ago, I noticed that my fridge would occasionally make a loud buzzing noise for about 10-15 seconds every so often. I (foolishly) ignored it, and about a week and a half ago, my wife called me to let me know everything in the freezer was thawing out and the fridge was warm. I did a lot of research online, and the problem sounded like the PTC start and/or Overload device was bad, so I ordered a kit that had these two pieces plus a jumper wire to convert the connector to the right size blade.

I got in the kit, and after trying to make sense of the directions, got it installed. When I say "try to make sense", I'm a pretty technical guy and should have had no problem figuring it out, but in all the directions and all the illustrations in the directions, the terminal blades should be on 1 and 3 of the PTC start device, but my PTC device only has terminal blades on 2 and 3. I don't know if my piece was bad, or if someone goofed on the directions?

Anyway, I hooked it up, substituting the terminal on 2 for the one supposedly on 1, since that's all there is. Plugged the fridge back in, and it sounded like the compressor came on...for just a minute...then right back to buzz, stop, buzz, stop, just like before.

Did I do something wrong? Here's the things I've already checked:

The new PTC device has 4.9ohms resistance from terminals 2 to 3.

The compressor has (**see note in reply below) resistance. I can't see a ground from the compressor itself to anything else. There is a ground wire that splits off the power line right before it plugs into the wiring harness that then leads to the compressor, but I don't see any other ground wires.

The condenser fan is working fine. Turns on when the fridge is plugged in. The power for the condenser fan comes directly spliced from the same wires that feed into the run capacitor and then back to the compressor.

The old PTC start I took off didn't look damaged at all (as I've heard others say theirs was nothing left but ashes and terminal connectors). The overload device also looked ok. The old PTC has 5.5ohms between the terminals as well.

I ohm tested the run capacitor at 2000K. It (slowly) ramped up from 0 to infinity and stayed at infinity, and did the same if I switched the poles. When I say slowly, it took a good 20-30 seconds to go from 0 to infinity. I don't know if this is normal or not.

I'm not sure what else to look for. I'm considering replacing the capacitor as a last resort, as its pretty cheap, but other than that I'm at a loss. Did I get a bad PTC relay? Could it be the capacitor? Or am I just SOL and its the compressor?

Any help would be greatly appreciated. Thanks!

Ahhh, I suppose it might help if I had remembered to switch the setting down from 2000K to 200. Oops! Retested, and I got 4 ohms from common to one pin, 5 ohms from common to other pin, and 9 ohms from bottom two pins. And infinity from all pins and body. Hard to stabilize numbers, mostly from limited hand clearance area, but these seem to be the numbers they kept hovering around.

**on that note, I went back and retested the PTC relays. Forgive me, I'm still new to all this stuff. :) The old PTC relay has 5.5 ohms between the two blades. The new one has 4.9.

It may be worth while replacing the capacitor, as you said it is not expensive.

The capacitor does look OK when you checked it with your meter.
The problem is that they can break down at higher voltages and your meter probably only put 9 volts max on it. In order to check it properly you need a special unit which applies operating voltage and then gives capacitance and leakage info.

This is a long shot but I would give it a try.