Hi;

New to this site, I just bought my 55 a few months ago.  I have an issue with the temp gauge.  The gauge reads just to the left of the H position, even after the engine has reached normal operating temp, although it does move a little bit.    When the engine is started the gauge still reads on the H position.  When I short the wire to gnd going to the sending unit the gauge does go to the C position.  This car does have just the one sending unit,  not a thermal switch on the passenger side.  But the sending unit   does have two terminals on it with about 1.7 ohms, cold, measured between the two terminals.  It would seem that the sending unit is not the correct one but I'm not sure.  Any thoughts would be appreciated. 

Thanks
valencia

Some of the early Yblock sending units had two terminals.  You can use either one


54 Victoria 312;  48 Ford Conv 302, 56 Bird 312
Forever Ford
Midland Park, NJ

I did try the other terminal but the gauge still doesn't read the correct temp...Anybody have any other ideas?

Make sure there is no sealant or teflon tape on the sending unit threads. The sender needs to be grounded to the engine.

I’ll suggest trying another sending unit.  There’s a chance you have a 1956 sending unit which will read differently than the 1954/1955 units.  They almost look identical when sitting side by side.  Do you have an ohm reading for the unit you have at ambient temperatures?  That may help to isolate if you simply have the wrong year sending unit in place by comparing to a known ‘correct year’ unit.

Lorena, Texas (South of Waco)

Thanks for the idea.  I had measured to gnd before  and it is a short from body of sensor to engine gnd.  Thanks again.

Thanks for the reply.  It is also my belief that the sending unit is bad/wrong type also.  Now I just have to find one for this model/yr. I have not taken a meter reading when the engine is at normal temp. but a good idea, I'll do that .   Again thanks for your reply.

Thanks to everybody who responded.  Just a FYI, I did replace the temp sensor on the engine and all is well.

Valencia