The Stovebolt Site Forums The Shop Area The Electrical Bay 6v system with 12v fuel sending unit

I'm getting a full tank reading all the time. I installed a generic fuel sending unit in when I first got a new tank without thinking about the fact it was most likely for 12v systems. I installed an extra ground wire just to make sure but don't think that was my issue.

Can I install a resistor or even a variable resistor in the hot line from the gauge to dial in the right reading?

Thanks, Larry
1949 3600 completely stock

Larry what is the ohm value/range for the sender you bought?

http://www.tanksinc.com/index.cfm/page/ptype=results/category_id=159/mode=cat/cat159.htm

Took me a while to find the info.

Empty - 240 ohms; 1/2 - 130 ohms; Full - 33 ohms

Thanks, Larry

Sending units don't care about voltage. There is NO voltage to a sender. The gauge needs whatever voltage it is designed for. The gauge must also match the ohmage of the sender. Your stock gauge is 6V 30 ohm. The sender must be a 30 ohm for it. But it sounds like you have changed something if you bought a generic sender instead of a stock sender. Can't help you if we don't know what you have.
There is a stock 6V gauge, a stock 12V gauge and a stock sender, that works for either gauge, available for 49-53.
Your signature says "completely original".
1. 6V or 12V system?
2. Original "new tank"?
3. Original gauges?
4. Why did you buy such a funky sender?

Your fuel gauge is made to work with a 30 ohm sending unit. The sender should provide no resistance when in the empty position (~0 ohms) with progressively increasing resistance as it reaches full resistance (~30 ohms) at the full position. Generic 30 ohm sending units are available from all of the vendors.

Ok thanks for the info, I definitely didn't understand this. So the "always full" reading makes perfect sense. I'll replace the sending unit with a 0-30 ohm unit and should be fine.

I changed the sending unit to the correct 0-30 ohm sender and made sure it's grounded. It is currently reading 20 ohms and the tank is about 1/3 full (from looking down the hole). However it is still pegging the gas meeting to full. When I shut off the key it will go back to empty. It also sticks after I tune of off and I have to tap on it to return to empty sometimes.

Any ideas? Thanks Larry