That "tension wire" is a capillary tube. It senses the coldness down by the evaporator and shuts off the compresssor so the evaporater doesn't turn into a block of ice as you use the AC. If you take off the pass side center console side panel and perhaps the panel underneath the glovebox, you'll find a black sticky tar like substance wrapped around a hose that comes through the firewall. I'm sure this is where the end of that capillary tube lives but I've never removed it. My guess is that it is wrapped up, all serpentine like, around that pipe and if you remove enough of the black sticky stuff, you can uncoil it and remove the switch. If you're at the pick-n-pull, it should be easy enough to investigate further without risking damage to your own car.
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Bob W.
'91 744T 173K
'82 245Ti 238K
'81 245 GLT, non-turbo 275K
'67 122 wagon