1980 Fuel gauge pin out.
 

The schematic I found on this site says that the fuel level wire is pink but when I put that on my gauge it shoots to way over full. Is that the right wire? I removed the stock gauges and put in all aftermarket. Also, how to keep the speedo cable on the gauge? The stock gauge has a little clip but the aftermarket is threaded. Ideas?

Re: 1980 Fuel gauge pin out.
 

It sounds like the wire you chose is either wrong, its grounded out, or the sending unit is bad. That's about all I can help with, unfortunately.

Re: 1980 Fuel gauge pin out.
 

Well strange thing, I went out to go to work this morning and it's working. I'm kinda confused but it's working so we'll go with it. lol

Re: 1980 Fuel gauge pin out.
 

A fuel gauge going way past full is normally a sign of an OPEN circuit in either the sender, the tank ground, or the wire to the sender. If you have a dual tank switch, can also indicate a bad switch.

You might have the dreaded intermittent connection problem.

Re: 1980 Fuel gauge pin out.
 

Usually the intermittent is the tank to frame ground wire but the 1980 and older dual tank switch can do this too.
The tank still makes contact through the straps sometimes hence the intermittent function. The switch will do similar things but I'd check the tank ground first.
Next time it presents the needle in the 3:00 position grab some jumper cables and hook the pinch weld on the tank to a clean spot on the frame with them. Betcha it gets all better. It may stay that way when you remove the jumper cables just to mess with your head.

Re: 1980 Fuel gauge pin out.
 

Good info as always. Any ideas on how to connect the speedo?

Re: 1980 Fuel gauge pin out.
 

Which end of the cable?
Inside the cab... The speedometer cable simply plugs onto the speed head on the back of the cluster. There's a steel spring clip to hold the cable end in place. You depress the open side of the clip to pull the cable off the speedometer.

Under the cab... The cable screws onto the speedometer output at the transmission tailshaft... or the transfer case tailshaft on 4x4.

In the engine bay... If you have the 1968-1982 mechanical transducer CruiseMaster Cruise Control on the LH inner fender the speedometer cable is in two pieces. One piece runs from the transmission/transfercase to the transducer. The second piece runs back out of the transducer and through the firewall to the speedometer.

Re: 1980 Fuel gauge pin out.
 

Yeah, I've put aftermarket gauges in the truck and the after market speedo doesn't have the clip. I guess I'll have to have a cable made with a screw in end.