[Alcaeus]

I recently had a guy come out to look at my HVAC unit. He said that my blower motor might be going bad and my contactor and my condenser fan motor were caput then generously offered to fix it for me for 1500 dollars

I found a granger and purchased both parts for $91.00 and installed them myself.

I slip in the breaker and the whole thing come on purring like a kitten. At this point I go into my house and feel cool air coming out of the vents.

Here comes the problem.

Suddenly I hear a muffled bang and smell an electrical fire. I go to my AC and the thing is still running but the blower motor is now not moving.

I purchase a replacement thinking that its the motor just going out and put in in for $70.00. I slip in the breaker and the whole thing comes on. Im sitting in front of the open panel that the blower motor is in and i hear a muffled explosion and see fire inside the blower motor!

I'm assuming that there is something wrong with the way I wired it. I'm almost positive that I put the wires on exactly how they were on the original parts.

I did get a new matching capacitor and I made sure that all of the specifications on the motor were the same.

Is it possible that the contactor has something to do with it? or that two different speeds are trying to go on at the same time and shorting the motor?

I tested the voltage on the board for the cold hot and com lines. both Hot and Com read 121 volts but the cold was showing 4v max. Is my board bad?

Also I plugged in a new motor with only cold wired to a speed = nothing happens.

I wired up hot to a speed and my motor turned on but was making bad noises and started to smell. The motor was being burnt out! I pulled the breaker before it could go to far.

What does that all add up to for you guys?

[icehouse]

A make and model number helps. Does this unit have a fan control center ?
Please post all information so as not to send you on a wild goose chase.

[Alcaeus]

The contactor was the problem. I think that one of the poles was bad and I wasn't getting enough voltage to the motor. The motor amped itself up and burned out because it was trying too hard.

I replaced the contactor and the problem went away.

Thank you all for the help.

[icehouse]

A good maintenance twice a year should prevent future problems. Meaning turning unit off,disconnecting power,remove control panel,clean and tighten connections, oil fan motor.