My 24v transformer blew on my 10 year old Trane system. I replaced it and the unit ran for a few seconds and then the transformer started smoking and everything stopped. This transformer is now shot too!
I checked the wires coming from the control unit to the motor relay on the compressor and got 0 ohms resistance across the wires. I then went to the compressor and removed the leads from the control unit to make sure that the wires weren't shorted somewhere (the wires were 24v yellow and orange/control t-stat wires) and the relay measured 0 ohms across the 24v terminals.
Should the relay measure 0 ohms across the 24v terminals? This seems like it would be bad as it basically is like a shorting my two 24v leads together (since no resistance is there).
I checked for cross shorting of all t-stat wires and found no shorts. The problem only happens when the t-stat tells the AC to turn on. Just in case, I replaced the t-stat but that did not fix the problem.
Where else (or what else) should I be looking for? What is causing this thing to short out?
Thanks for ANY help!