I just remove the wires. One from each side of the coil. The reading was 1.2 M Ohms.

What does everyone think?

Just apply 24 volts to it. If it slams shut you know it is working and not fried. If the leads spark a lot when you touch the 24 volts to it then you know it is toast.

fljrc3:

Flrjc3: try removing the y wire first which will isolate ouside low voltage. The condenser unit has low voltage board for condenser fan which I have seen short out.

I have a couple of questions for you if you please. First I assume that you have a furnace with a hot surface ignitor? And next have you ever noticed a test post on the circuit board?

With the low voltage fuse blowing it has to have ssomething to do with the low voltage lines of cor coils.

If I were you I would disconnect the Red, White. Green and yello wires form the low voltage terminals on the circuit board.
Next I would jumper from the red to the white, hold this about the length of time that it takes for the fuse to blow. If it does blow notice if the hot surface ignitor glowed at all. Also diod the inducer motor on the vent come on and run

If this has not told you any thing I would suggest putting the wires back in place and then try to find the test terminal and follow the instructions on how to use it and see if it will go all the way through the cycle. Notice it will not turn on the gas in the test.

I hope this helps

The original poster hasn't updated this in over a week. Bringing up old/dead threads is rather pointless as your answers usually fall on deaf ears.

Don't jump to conclusions guys... maybe his internet service is really, really sloooooooow...

Don't you have a variable speed motor to be fondling?

You call it fondling, I call it Saturday night!

It's only Wednesday. Don't tire yourself out.

Wednesday? No wonder she's not home.

Knowing VS motors it probably broke down halfway home and can't afford to make it the rest of the way.

Witty... you are proving to be a most worthy adversary for VSM

Hi Guys,

Everybody relax. I haven't responded because the weather has been good here in Florida and my wife hasn't forced me up into my little crawl space of an attic to finish working on the HVAC system.

I finally finished this project on Sunday afternoon just prior to the football games.

I pulled one low voltage wire at a time off the printed circuit board at the air handler.

I attached a circuit tester across the low voltage fuse wiring and contiued removing one wire at a time until the short went away. As I mentioned before it was the yellow wire that went to the contactor coil that stop triggering the circuit breaker. I replaced the contactor and the short went away and the system works great.

In addition I replaced the Trane mercury switch thermostat controller with a Lighted Hunter LCD touch screen display. The system works like a new cadillac now.

Thank you all for your support and guidance. You saved me a lot of money, and I got a great education in the process.

Joe C.

I knew it all along. It's a gift. Your welcome. 4-11-26-32-38-49.