Just thought I might save someone from an uncomfortable crawl under the dash:



Stock temp gauge suddenly moved up to "H" while driving on the highway. First thought was; another thermostat failure! But, before I could panic, needle dropped back to normal. Symptom recurred intermittently, but predictably, and gauge moved too quickly to be a real indication of actual engine temp. So, I replaced the OEM 6V sending unit (NOS) first since my gauge was fairly new, and draining a little coolant seemed easier than the contortionist routine. PROBLEM SOLVED!

6 VOLTS/POS. GRD. NW INDIANA

I thought the NOS temp gauge would solve my problem but only half,mine is still not starting out on cold but does not peg all the way on hot when the motor is warmed up like it did before.  NOS gauge with a reproduction sending unit with a 60s instrument voltage regulator controlling the gauges since its converted to 12 volts.

Butchering up everything I can get my hands on in Dayton Ohio

Don't know about 12V units, but guy who sold me the NOS 6V sender claims the new repro usually reads too hot.

6 VOLTS/POS. GRD. NW INDIANA

If I can remember correctly the temp gauge ran about 3/4 with the original motor and 6 volts,with the new sending unit its slightly higher then 3/4 but is better then pegged all the way over to hot like it did when I ran 12 volts through it,I have a IVR controllong the voltage and need to see if its grounded properly.

Butchering up everything I can get my hands on in Dayton Ohio

Where did you get the NOS sending unit?  I'm looking for a 6V for 1955.  Also oil pressure sending unit.

Tom Sestak. Has an eBay store. Be forewarned though, as soon as I bought mine and we discussed his claim re: repros reading too hot (and dwindling NOS supply), he jacked his prices way up.

I think he is looking to get rid of everything and wind up the business, so maybe he will make a better deal if you buy complete set of senders & gauges? Could be handy to have reliable/accurate replacements on hand.

6 VOLTS/POS. GRD. NW INDIANA