I took my s60 to a shop with a faulty coolant temp sender.(30 degrees in the a.m. start up car, alarms go off pull car over overheating) two weeks later, same problem. He blows me off, treats me like a third class citizen. The only reason the shop is doing the work is because I’m waiting for a spine surgery. I’m on disability. Otherwise I would be. Under the hood I find that the mechanic cut the wires on my thermocouple before the plug, cut an old sender out of a different car at his shop, and wired it in mine to fix my issue. Here’s the question, can I cut the wires and solder the original back in? I thought thermocouples measure resistance and soldering them changes the resistance. Therefore you never cut and solder? Or do I have to trace those back and rewire the entire thing over? This mechanic could have replaced the original for $18.96 my cost. Instead I feel I have a major repair on my hands! Oh, it just so happens he sold me the car a month ago, I’ve had it to him three times, still same issues. Took it to another shop and they fixed some. But, I’m feeling like I got got by this guy. I will post pics. Also, when the auto parts guy gave me what he said was oem, it’s a black plug around a grey plug with very small female slots x2.

what I meant was put it back to oem with new sensor. Who knows what he did with the old one?

I just minutes ago found this. I was leaning that direction. I actually just told my wife I felt like an idiot because I can make all this stuff myself. I was a crane technician for several years after being a millwright. I know this stuff. I think it could be 10 months on pain killers waiting for a spine surgery so that my legs work correctly and I can get back into a manual. Ugh. The reason I didn’t do it myself.