The title says it all. I'm trying to troubleshoot a strange issue.

We sold a home in a different part of the state last year and purchased another home farther South the first part of this year. The home is a 60's Atomic Ranch that originally had no A/C. It was added at a later date and is currently a 1999 Trane over/under package unit. Most of the older homes in this area are set up this way.

The unit works very well and is actually a little too much for the house. When we bought the house I basically disassembled the entire unit, removed all the old insulation and re-insulated the entire unit inside. The unit is in overall "good condition" and worked flawlessly before re-insulating. Previous repairs to the unit are unknown.

About one week after re-insulating the cabinet, the evaporator fan would randomly not want to come on. Then, occasionally the evaporator fan would cut off while the compressor was still running. Learning that all Trane's of this vintage came with a factory hard start kit, I found that tapping on the hard start relay would cause the fan to come back to life. This made no sense to me, because I thought the hard start kits were designed to help compressor starting only? Anyway....

After putting up with several weeks of this I finally called a local A/C tech out. He put his tester on the fan and ruled that out. So, the fan is good (not drawing too many amps while running or at start up), the fan start capacitor is good (but not replaced by me). While he was in there fiddling around, he found that tapping on the other relay (timer relay?), the evaporator fan came to life! So he replaced that relay and $150 later I was good to go. This was all about 1 month ago.

Now, about 1 week ago the same issues with the evaporator fan cutting out while the compressor is running have started happening again. This time there is lots of "clicking" going on out at the unit and all of the clicking is coming from the new relay that was installed. If I go out there and tap on that relay, the fan will come to life again. So, for the past 5 days when the fan has not been working, I go out and tap on the relay to get the fan going.

OK.... Here is where it gets interesting! So, I have had the access panel for that relay removed, so I can "tap the relay" when I need to. Yesterday we had some hard rain and I forgot to put that panel back on. In a panic, I ran out there, Turned off the breaker and re-installed the access panel (in the pouring down rain). After turning the breaker back on, the unit has run flawlessly ever since! Not one hiccup and the fan and relay are both working fine.

So, is it possible that I have a weak or bad circuit breaker that feeds power to the unit? I would think that if the power were low or erratic that the compressor would not run, since it obviously draws more power than the evaporator fan?

Puzzled.... Sorry for the long winded post. Difficult to describe.

__________________
AJ

1985 300D (SOLD)