Removed the tape and reinstalled sending unit, no change. swaped the one from another 69 and no change. gage moves rapidly when car is runnimg, goes about half way when switched on. think it could be the gage? ive got a couple of spare clusters, gonna plug one in and see what happens.
On some cars there is a pigtail which plugs into the harness at the firewall and then the engine harness plugs into it. On those cars which had it, it is needed because there is a resistance in the temp sender lead required in order for the temp gauge to read correctly with the sender.
ok. i changed out the gage and the sending unit and the problem still exists. my car is a standard coupe w/351w. pretty much stock. i took a sending unit out of another cougar w same setup that works and still no change. i suspect its in the wiring somewhere. everything has worked fine since 2007. the car is only driven to shows and a few cruises a couple times a year. loss than 5k miles per year. it also appears that the gas gauge may be malfunctioning too, it shows 3/4 tank but im sure its less than that. i fill up every time i take it out so its usually less than a half tank when i get back. i will check for the pigtail at the harness tomorrow. thanks for your help!!