Good Afternoon,
So nothin in my dash works, I know why, the previous owner hacked the harness when they changed to a flatbed and it looks like it was done with a hatchet. Anyway, I tossed in an aftermarket fuel gauge and wondered, can you direct wire the fuel gauge in the stock dash (bypassing the printed circuit)? If I could get at least fuel and speed in the dash I could live with that. Don't like the dummy light setup on the other vitals anyway.

Thanks!

 

Should have mentioned...78 F-150

 

You’ll need a fuel gauge rated for the same ohm output as a regular ford sending unit in the tank. The sending unit in/ on the side of the tank will have two wires coming from it. One is a ground a should go to your frame. The other is hot when the key is on but it only gets pulsating 12v power. Meaning it will come on and off like a blinker kinda. Wire this to your positive post on your fuel gauge and ground your fuel gauge to the dash. Assuming the dash is grounding to the cab and the cab to the frame the fuel gauge should work. And you don’t have to tap into anything behind the dash, just the wire coming from your sending unit.

The temp and oil gauge can both be used independently of the dash. Cheapest way for the temp gauge is to get a mechanical one that will screw in in place of your factory electric gauge in the manifold/thermostat housing. It’ll have a tough black wire that can’t be cut that you can route wherever. The cheapest way for a oil gauge is the same way, but it takes either a thin plastic line or a custom bent brass hard line coming from your engine all the way to the gauge in the truck. Meaning any knick in the plastic line or crack in the hard one or leak in the fittings is gonna dump oil in the floor or the truck or all over the highway. I strongly urge to pony up the dough and buy a ELECTRIC oil gauge like the truck came with factory. No oil leaving the engine just a sending unit screwed into it. Mechanical temp gauges don’t take coolant out of the engine, so they are no more leak prone than electric ones.

 

Thanks! Yea I'm using the stock sending unit now with my aftermarket gauge, sees to work fine. I have Temp/Oil/Alt separate already too. The wiring was just so mangled I started fresh. It would be nice to use that dash gauge, so I'll give it a shot.

 

Give this a read