Fuels1ut
Registered Member
I'm a new member to CK5 but long time stalker. I'm curious if anyone has set up a fuel gauge for each tank to read regaurdless of which tank is selected. If so where did ya'll get the wiring diagrams and what not.
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
Duel tanks/gauges
- Thread starter Fuels1ut
- Start date
CGT80
1/2 ton status
Which vehicle and what year?
I have a 79 C20 pickup long bed with dual 20 gallon tanks. The dual tanks have a separate wiring harness to the dash. Two wires from the sending units to the switch and a wire to send power to the electric switch at the tanks. The fourth wire sends the correct sending unit signal back to the switch/tank area where it ties into the original sending unit wire that then runs back up the other frame rail to the firewall and in to the gauge.
You could run two wires from the dash switch to change the tanks over to your gauges. My factory wire was in bad shape, so I just cut it off and ran a short wire from the switch output to my gauge. It only needed to be 2-3 feet instead of 30 feet the way the factory had it.
I have all autometer gauges and I just had to get the fuel gauge listed for Chevys which I think may be 0-90 ohms.
I have a pdf of a very detailed wiring diagram for my truck. I think I found the link here. It is a factory repair manual diagram and lists everything. It is quite complex and it took a lo of studying as it isn't the best copy and it is not in color. It did clue me into how the truck was wired. It seems dumb how they did it, but I am no electrical engineer or car manufacturer.
I have a 79 C20 pickup long bed with dual 20 gallon tanks. The dual tanks have a separate wiring harness to the dash. Two wires from the sending units to the switch and a wire to send power to the electric switch at the tanks. The fourth wire sends the correct sending unit signal back to the switch/tank area where it ties into the original sending unit wire that then runs back up the other frame rail to the firewall and in to the gauge.
You could run two wires from the dash switch to change the tanks over to your gauges. My factory wire was in bad shape, so I just cut it off and ran a short wire from the switch output to my gauge. It only needed to be 2-3 feet instead of 30 feet the way the factory had it.
I have all autometer gauges and I just had to get the fuel gauge listed for Chevys which I think may be 0-90 ohms.
I have a pdf of a very detailed wiring diagram for my truck. I think I found the link here. It is a factory repair manual diagram and lists everything. It is quite complex and it took a lo of studying as it isn't the best copy and it is not in color. It did clue me into how the truck was wired. It seems dumb how they did it, but I am no electrical engineer or car manufacturer.
great info CGT80, my 1980 was the same setup. My only caution is there is no way of knowing which tank your drawing from. the one wire transfer valves can fail and you can run out of gas with a full tank showing on the gauge. I'd look into the newer 5 wire I believe transfer valve, the wiring in the valve is the switch for the gauge rather than the switch on the dash in older models. This way if it fails or fuse blows (in my case) the valve will stay where it is and indicate properly. If you hardwire the gauges you lose the change that would occur when the valve switches. If everything is working right with the 5 wire valve, you can just flip the switch to check the tanks, it should not stumble.
Fuels1ut
Registered Member
It is an 81/82 with some shotty wiring. I would just like to know how much fuel is in each tank all the time (I run them dry alot). How hard do you think it would be to wire in the new xfer valve if I have the single wire? I have always had concern of it going out when I need it to work.
I did some searching, your truck should have the newer 5 wire valve already. http://67-72chevytrucks.com/vboard/showthread.php?t=559333 this link has some good info on it. If you still want two full time gauges there may be a way to piggyback gauges, and retain the main gauge as the checking gauge, but that's beyond my skills
