The Stovebolt Site Forums The Shop Area The Electrical Bay determine if gauges are 6 or 12 volt.

Hey guys.

My truck has original instruments, but most of 'em dont work.

Speedometer doesnt work, but i guess thats because the plastic gear in the gearbox is gone . does anybody know where i can order it? and what its called?

These work:
D/C gauge
Oil pressure Gauge

These dont work:
Fuel
Temp.

I find fuel and temprature gauges quite important, and i'd like to see them work. But i've got no idea of how i should make them work again. They havent moved in at least 15 years. Are they just "stuck", or dont those 2 gauges work on 12 volt? or is there another problem?

I'm hoping i dont have to rebuild them, because when i got saved up a bit of money i want to buy new instruments next summer. But i'd like to be able to get all the information when im driving.

Raoul.

Raoul,

It is best to state what you are working with. Many people have information in their "signature" but they ask questions about other projects (trucks, engines, etc).

What year engine? 216 (6v, originally)
What year gauges? 1951 (6v, originally)

6v or 12v electrical system? (12v, now)
If you do not know, people will post ways to determine this.

Fuel gauge - is voltage sensitive. If it is 6v and used with 12v it will most likely stop working. 6v and 12v reproduction gauges might be available. If it has been fried, it is not repairable.

Temperature gauge - mechanical sender until mid-50s and then electric sender. The sender hole got larger when changed to electrical - an adapter for the older mechanical tube is available.

If you are missing your sender tube, your need either a new tube and/or a new gauge unit (I think a broken or missing mechanical sender tubes means you need a new gauge - someone will clarify/correct).

as Tim says, you've likely fried the fuel gauge by using 12V on it without a dropping resistor, although it could possibly have a bad connection to the sender which could have saved it, you can check the sender circuit with an ohmmeter - if you find an open circuit, determine if it's the wire or the sender that's open, and get a proper dropping resistor before you hook things back up

if the original style mechanical temp gauge still has the sender tube attached and in place in the engine, it's dead and not repairable by we common folk

and don't assume the speedo problem is the trans gear [driving or driven gear], it's more likely to be the cable or the speedo itself ... disconnect the cable from the unit, drive the truck and feel if the cable is turning, if it does the problem is a gummed up or broken speedo head - if it doesn't turn pull the trans end and try turning the inner part with a drill motor - worth pulling the inner part out and cleaning it well regardless

Bill