Hello group, I am a new member, just getting started on this site, I hope to tap in to information from users. I have in inoperative temp gauge in my 56. I have the stock sending unit and gauge package. How can I test sending unit and gauge? Where can replacement stock gauges and sending units be found? Thanks, Larry

 

If you want to stay original, So Cal Pickups at 1-800-762-2549 can fix you up with a recondition gauge. They used to require you to send in the old one as a core, I'm not sure if this is still so. Another route is to take a working gauge from a later truck & simply change the facing. The problem with that is starting with the 1957 models, the needle rests on C instead of H & you'll also need a B9MZ-10804C voltage regulator which is still made.

Bob Drake at www.bobdrake.com has the correct temp sender unit. If you have a later Y block & the sender doesn't mate to the hole, an adapter is available either thru a supplier or maybe ar your local hardware store

 

To test the sender unit, you can hook up an ohmmeter to the guage with a cold engine;start the engine and verify if there is variable resistance as the engine warms up. I don't know the specific readings. At least that would test the sending unit and help isolate the problem.

Tim in Burien, WA
'56 F100 (now a big back window Soon to have a Mustang II clip under it!)
Check out my website for 2001 F100 Supernationals pictures and more:
www.users.qwest.net/~tkbowman

 

I'm just curious on this topic because I recently tore the temp sensor off my old Y block and screwed it in the 302 I have in my 56, but it doesn't seem to work. I noticed there are two prongs on the end of the sensor, so maybe I have it wired wrong. I simply put a clip on one of the prongs and that wire runs to the gauge in the dash. Is the other prong supposed to have a grounded wire running to it? Thanks

Craig

 

The temp guage sending unit is a variable resistance unit with the case making the ground circuit. There are 2 prongs but both are the same circuit (the sensing wire from the dash gauge). Does anyone know the actual resistance values to test for? Do these old gauges work opposite of new types? Larry

 

I tested a temp sender by having the sender in a pot of water on the stove and a ohm meter connected to it. Heat the water and watch the meter for a change in resistance. If it doesn't change then it is shot. Use a candy thermometer to read water temp. Should see resistance start to change at approximately 100 degrees F. This will verify operation up to 212 degrees F which is the boiling point for water.

rogerf100