Lately there seems to be a rash of oil and temperature gauges, including my own, flittering up and down. I read something in one of my manuals about taking the precaution, when installing a new sending unit, to use an electrical conducting sealant. I guess this would be primarily for the single wire sending units that rely on a good ground connection as a return path for the signal. Yet in my other manual it shows a picture of an installation of a sending unit and they are wrapping teflon tape around the threads. Could this be the problem of so many of these units flittering around? And is there actually a sealant that's electrical conductive? Just a thought.

 

I like your take on this Don, I too have wondered the same thing. I used Loctite PST #565, which is a liquid, controlled strength, anaerobic sealant for METAL threads, on my 78 Mercury Zypher, when I "T" 'ed in an electrical oil presure sending unit at the idiot light senders location about 20 years ago. (YUP I still have the vehicle) I chose the liquid sealant over tape, as it fills in the space between the thread root & crown, but is squeezed out, where the threads touch, thus making good electrical contact. This may not happen if teflon tape is used IMHO. I've not seen automotive specific conductive sealant for his purpose advertized, although there are expensive graphite, nickel, & silver loaded sealants for industrial & aerospace use out there that could be used. Anyone know if there is a product out there specificaly designed for automotive use???? The Loctite 565 I used comes in a small .20 oz package item # 56507 if anyone is nterested in using it on your rides (METAL ONLY) sending units threads. It's for industrial use, so you may have to go to a indrustrial supply to get it. In my area, you can get it at the likes of Dixie Bearing.