favor please

[1969 modified]

I also posted this in fuel guage reply. Could someone please disconnect their brown wire from the tank send unit at the special notched plug on the side of the fuse block and measure the voltage on the remaining male lug in the fuse block.

Also does anyone have the actual wiring diagram of the tank sending unit and the fuel guage. I'm trying to get it clear in my mind but having trouble. If I had the circuit drawn in my mind or paper I could troubleshoot it pretty quick. I'm not understanding why they run the brown wire from the tank sending unit directly to the fuse block, because I don't think the brown wire has 12 volts on it.


Thanks

[sneakysnake]

The principle is 12v goes onto gauge, then to sending unit, the sending unit is a varible resistor o-90 ohms to ground. as the fuel level changes the value of of ohms change,letting more or less current to ground, the gauge reads this voltage drop or gain.

[sneakysnake]

not real clear, but a wiring diagram
http://www.geocities.com/chevroletc1070/wiringdias.html

[tomatocity]

Originally Posted by sneakysnake

The principle is 12v goes onto gauge, then to sending unit, the sending unit is a varible resistor o-90 ohms to ground. as the fuel level changes the value of of ohms change,letting more or less current to ground, the gauge reads this voltage drop or gain.

E=IxR
I=Amps, E=Volts, R=Ohms

[Big Block]

It's 9.6 volts if you put it to a 12 volt sorce you will smoke the sending unit. How do I know, because I did it accidentaly. I pluged it into the constant 12v on the fuse block. B.B.

[1969 modified]

Thanks for the help. I located my problem and now the guage is working great. When my two sons were helping install the new seat and bolt hole locations, apparently the sending unit wire got pinched to ground underneath the seat support.
Thanks for everyones help.