My front air conditioner, blows air, but it's not cooling. The rear air conditioner works fine. I tested the capacitors and the compressor side capacitor is shot. The fan half of that capacitor is good. How do I test the PTCR relay? When I search for information on the Internet, the answers are for refrigerator relays. I'm measuring 42 ohms at room temperature on the PTCR, is that in range or too high?
The Phillips capacitor that was in series with the PTCR tested good.
The PCTR is not a relay, it is a big resistor that increases resistance as it heats up with current flowing thru it to the compressor. Doubtful it went bad. Replace your cap and you should be good to go assuming your compressor is working.
I changed my run capacitors on both mine which solved the issues. Ice cold air now
Reused the PTCR resistor and unit now running and cooling. Hopefully nursing these 25 year old units for another season. Following the replacement options thread with interest.