I had to replace the transformer on my furnace, the little switch beside the fan the on and auto was damaged too I couldn't find one so the man I got the transformer from said to just by pass it and tap it off,, well when I cut the air on ,the fan will come on automatic,, when I cut the heat on the fan will not come on, will I have to put one back on for it to work??

Need more info,

Are you stating transformer, instead of thermostat?

I'm confused.

Post is old