AC issue

[mrdman2442]

Wondering if you could help me out, I have a DGAA Coleman series furnace in a single wide home.

My problem is that when the thermostat is turned to cool the circuit board fuse blows, but when turned to heat the furnace starts and runs fine. The ac worked last year but the air from the vents was only 15 degrees celsius. This year it wont even turn on.

I'm thinking a short somewhere, so I disconected the two leads from the board out to the condenser unit but the fuse still blew so its not on that line, Any other ideas? Can the board fail internally, I checked and found no signs of scorched board or fried electronics. Any help is appreciated.

Mrdman2442@Yahoo.ca

[Robert]

Hi,


First trace all wires in 24vac low voltage circuit. and look for any bare spots, especially at entrances to unit.


At t-stat, turn power OFF, remove Red, Yellow and Green wires and tie/tape together. Then restore power and see what happens.

IF it still blows fuse, transformer and board and wires to/from each is all that's left.

Then if nothing found, you'll have to isolate each component until you locate the short.



Thanks for inquiring,
Robert