Hi, I have a old 1976 made Tappan CM 24-43 T AC unit and recently it wont turn on at all. What i did i got inside of it and was able to manualy engage a spring loaded switch and ac would come on fine. i am trying to find out what could cause the unit not to turn on automaticaly per thermostat and what would be the solution and if it is cost effective (i am not sure how much would a new ac cost for a 1000sq ft ranch)
The contactor coil is bad. When it goes bad itn will not pull in the contacts. When you manually push it in it works but will not hold. replace contactor and all will be well. Not expensive or hard to do. Just replace with same as you take out. ie single pole or double pole.
Dear lolo,
I was unable to get your model to come up. Possibly due to the age.
In most cases it does have to do with the contactor. You might try that before having a technician come to your home.
To get a new contactor you might see if there are any numbers off the old part.
Could be a bad thermostat. Check the coil voltage(24-28vac) @ terminals on each side of contactor. If you don’t have this voltage the contactor (relay) won’t pull in. Be safe!
I have same problem with a old model granita machine i have side by side relays one will not engage i took it out to try and find manufacturer but no one can figure out who it is the only description is R-O the contact coil is fused on to the rear of the sprng loaded relay and cannot be removed with breaking it open any suggestions:)