36 Series 40 Gas Gauge

[Rock10]

Our 36 was converted to 12 volts when we got it. Several things weren't hooked up so I don't know how complete the conversion was. Does the 6 volt gas gauge need attention or will it work fine with 12 volts? We have purchased a new tank and sending unit.

Thanks

[37_Roadmaster_C]

It will need 6 volts not to burn out the gauge. It may work with 12 volts, but its life may be limited. There are small converters just for the gauges available. Others on the forum should chime in with better answers.

[Bloo]

Yes, you'll need to knock the voltage down to 6 volts or risk burning out the gauge. I have heard of people using a "runtz" voltage reducer, but reviews have been mixed. It is likely to work better than just a resistor. The sending unit should be fine as is if it is correct for the car.

[Ben Bruce aka First Born]

 My Runtz has been in for 10 yeas,  20,000 miles. Still works.

 

  Ben

[Rock10]

Is the gauge adjustable? Can it be serviced or repaired? Do you have to take the instrument panel out to remove it?

[Bloo]

It is not meant to be serviced or repaired. If you are crafty and read up on balanced coil gas gauges, anything is possible.

 

You feed the gauge 6 volts and a good ground. It grounds to the instrument panel somehow when it is bolted in place, and a close inspection should show you how and more importantly where the gauge gets it's ground.

 

If you then ground the wire that normally goes to the sender the gauge should go to "E". Leaving the wire ungrounded should peg the gauge. 30 ohms of resistance to ground should make it go to "F". Usually they work or they don't.

 

 

Edited May 4, 2021 by Bloo (see edit history)

[Rock10]

We need to reinstall the temp gauge. (it wasn't there when we got the car). Do you have to remove the panel to install the gauge? That would give me a chance to closely look at the gas gauge.

 

[pont35cpe]

I`d say remove the cluster. On the `36 the gauge needle slip in between 2 pieces of glass, it`s kind of a trick getting the needle between the 2 when installing a gauge, needle can be bent/damaged very easily.

[Rock10]

I installed the gauge resistor and the response looks better.

It shows about 1/16th of a tank at empty ( the lowest reading I can get out of the sending unit) and I adjusted it to read about 1/16th over full at the top. We can live with that. Very smooth action up and down. Now have to get the new tank installed.

Thanks for the help.