Testing a Temp Gauge

[Steves46]

My 55 F100 (223 in-line 6) has an aftermarket temp gauge under the dash and what I would like to do is replace the aftermarket sending unit with the original 6 volt sending unit. I believe I found the wire that connected to the original sending unit. So before I do anything else, I would like to determine if this is the correct wire. If I was to hook a jumper wire from the battery to this, should the needle move on the temp gauge after I turn the key on? I would really appreciate any help.

 

[BOSSY]

NO NOT BATTERY POWER! With the key on hook a jumper wire to that wire and watch the gauge and just ground the jumper for a quick second and the gauge should peg hot. This tells you the gauge and wiring is good. You need and original sender for your 55 to work with the original gauge.

 

[Steves46]

Thanks. As soon as I posted the question, I realized that power was a no-no! I will quickly touch it to a ground.

 

[paul2748]

Do you want to use a original type sending unit with an aftermarket gauge? Probably will not work correctly as the sending unit may not be compatible with the gauge.