12 volt gas gauge to original sender???

airbrushguy

I've converted everything to 12 volts on my '49 262 and installed a new 12v gas gauge of the same ohms as the original. Do I need a voltage reducer and where should I put it?

Thanks

Park_W

The instruments from '36 to '50 are designed to handle some variation in input voltage, so you might not need to do anything else.  Have you checked to see how accurately they're showing now, with nothing done except the new sending unit?  If they're showing high readings, or if you just want to be conservative, measurements I've taken show that if you put a 15 ohm resistor in the power supply wire for the gauges, it will result in a good operating voltage for them.  Resistor should be rated at 5 watts or better.

airbrushguy

Thanks Park, I forgot to mention that I still have the original sending unit in the tank. I did get a 12v gauge with the same OHM range as the original gauge was. Unfortunately I did not drive the car enough before I changed everything to 12v to know if the gauge worked originally,

Park_W

So, is the new gauge working well?  Reasonably accurate?

airbrushguy

no, the new gauge is far off

airbrushguy

Gas gauge needle shakes all the time and is about a quarter tank off!

Anyone?

Glowplug

Go to my website http://hudsonrestoration1948-54.com/index.html#MAINTENANCE and select - Fuel Systems. On that page at the bottom are two information sheets for King-Seely gas gauge and sender operation. There you may find the solution to getting the gauge to operate correctly. I would suggest using a power IRV to stableize the voltage. Good luck

Park_W

The problem may be that the original gauges and senders do not operate on a resistance ("ohms") basis.  They have a bi-metallic strip system that makes and breaks the circuit at a rate that varies with the position of the tank unit.  The gauges needles are heavily damped so that they don't wiggle as the make-and-break system operates.  If you have an original-type sending unit and a modern-type gauge, it's probably going to behave as you've described.

airbrushguy

Park_W said:

The problem may be that the original gauges and senders do not operate on a resistance ("ohms") basis.  They have a bi-metallic strip system that makes and breaks the circuit at a rate that varies with the position of the tank unit.  The gauges needles are heavily damped so that they don't wiggle as the make-and-break system operates.  If you have an original-type sending unit and a modern-type gauge, it's probably going to behave as you've described.

So where would I get a sending unit from?

Park_W

You need a resistance type sending unit for the '51 -54 cars.  Paul Schuster in PA has them.  Check with him to confirm his units match up with your gauge, with regard to resistance range.

hethudson1957@aol.com (remove the "het" for actual address).

airbrushguy

Thank you Park.