I had a new aftermarket radio installed on my 2002 hL and the temp went hot so I told the tech and he said the Potentiometer probably needed looked at. When I push on the temp. dial it will instantly turn cold. It has gone hot/cold the last few months also. I do read these posts and have tightened the nut behind the temp dial last year (it was loose) so now I think it is the Potentiometer that is the culprit. Any ideas on a cost to have a service guy fix it (shouldn't be much) and is there a particular name for this repair?