How to test 1949 Ford Sedan Dash gauges

[Snuffysez]

We bought a 1949 Ford Sedan. Someone had converted the car to a 12V system. I know there is a Voltage Reducer to take care of all three gauges-fuel, temp and oil. Q-How do we test to see if the present gauges are working and not burnt out.

 

[rotorwrench]

I test them using the original type senders (I have spares ones). For the temperature guage I used a hot plate with a pan of oil. For the pressure guage I use the hydraulic pump portion of my old Port-A-Power to get a pressure reading with a T in the line for a regular mechanical pressure guage. I always have a bunch of alligator clip test leads around to connect every thing up electrically for the test. The water temp indicator always reads full hot until it's connected to the single post sender and power is applied. The twin post sender is just a temperature sensitive on off switch. When it gets hot enough (230 degrees or there abouts) it opens the circuit and lets the gauge go to full hot. The ammeter it really just an inductive charge indicator. The wire just passes through the brass ring on the back of the guage and induces a current either plus or minus. If the wire is put through the ring the wrong way it will read in reverse.

Kerby