[fixerguy123]

No ground at Compressor ground terminal on PC board inside furnace.

24V found at Y wire / positive to compressor terminal with meter grounded to chassis when T-Stat in in "cool" mode.

Jumper from Chassis (internal transformer) ground to compressor ground wire makes compressor function normally.

No issue with heat side. All wires from T-Stat test as normal.

Can I assume that the PC board in the furnace needs to be replaced?

[fixerguy123]

Originally Posted by fixerguy123

No ground at Compressor ground terminal on PC board inside furnace.

24V found at Y wire / positive to compressor terminal with meter grounded to chassis when T-Stat in in "cool" mode.

Jumper from Chassis (internal transformer) ground to compressor ground wire makes compressor function normally.

No issue with heat side. All wires from T-Stat test as normal.

Can I assume that the PC board in the furnace needs to be replaced?

I was reminded that I should have said "I had to jump the COMMON compressor wire to the chassis to bypass the "C" terminal." I was thinking in terms of DC wiring rather than low voltage AC when I used the term "ground"

Anyone out ther have a schematic for this board? Lennox 48K98 . This is a friend's furnace. I'm just helping someone who's down on their luck.

All other BCC board related functions seem normal. If this contact is the only one made by this terminal, can I simply make this temporary contact more permanent and save her some money?