No voltage to zone control motors

[micrometer]

I was cleaning up my honey-well V8043 motors on a few of my power heads. They were working fine when I re-installed them. I checked the two wire motor leads on a few of them and was getting 26 VAC (should be 24 VAC).

One had a bad end switch so I swapped it with a good one. When I installed it all five zone controls stopped receiving calls for heat. I checked a few for the 26 VAC but showed zero. I followed the traces back to the transformer. It also showed no voltage (AC or DC). The transformer was quite warm so it seems to be powered up. I'm use to working with DC so there is no bridge rectifier from the transformer.

Should I be checking anywhere else to find my missing AC voltages?

 

[Chuck]

My guess is that whatever you did to the zone valve with the 'bad end switch' has resulted in a short circuit across the 24V feed. Ideally, this would blow a fuse but, if it hasn't, your overheating transformer is a likely consequence.

If the end-switch has three wires then there are 6 ways to connect them and only one will be correct.