My Ruud 10seer has been running pretty well. But a week ago the fan stopped coming on when the thermostat called for it. I replaced the contactor because the old one looked a little burnt. I didn't think that was the problem, because the sping bridge was not welded shut- in fact when I push it down with a screwdriver, the fan comes on. The new contactor didn't change things. [IMG]http://i176.photobucket.com/albums/w181/jonrw/WP_001118.jpg[/IMG] Here's a picture and test results. No voltage at the coil- assuming I am testing it right for 24volts. One flowchart online says I should check the control transformer and control fuse. Before I do I wanted to ask about the high pressure switch- I think it has tripped. The dog chewed up the high pressure reset button a few years ago. Seems it can't be replaced without evacuating coolant- can I activate the switch by momentarily bridging the connectors at the rear of the switch? There are two brown wires and a copper tube running to it.

I had a tech out and he did a visual inspection; no luck. He thinks the problem is in the wall somewhere. His solution is to replace the entire line set for $1k. I bought a cheap electronic tester and tried soap bubble tests on the connections outside. The coils of the compressor look great as the units are pretty new. In the attic I got 2 hits on the tester around a small silver wire that must be part of a sensor; it joins the larger gauge copper and is covered with some sort of silicone tape. Any thoughts on what to do next?