'72 Printed Circuit Fuel Gauge Wire?

Hello all! Im new to this and thought I'd come in and ask for a bit of help.

I've been working on trying to get my fuel gauge to work on a 72 mustang. I came across this on the printed circuit, seems like they soldered a wire in attempt to ground it? The circuit board is burnt as you can see in the pics so I have ordered that as well as the IVR.

My question is, why did they do this and can I leave this off when i install new printed circuit? Am I going to burn up the new one?

Some background, before I got to this point I thought it may be the fuel sending unit, I bought a new one and unhooked plug at tank and "dry" tested the unit and it popped and blew the new unit.

Well, someone butchered up that wiring really bad and wrong. The fuel line post is the post for the fuel sending unit, which is now tied to the brake master cylinder line indicator power line. Wrong wrong wrong.

Replace the circuit board and I suspect you'll be fine.

Hello & Welcome to the best site for 71-73 Mustangs!

I would look at the whole harness before putting in the new circuit board. Somthing caused the burnt traces and the po added that wire afterwards to get something working. Installing the new board first may just let the smoke out of the new card and waste $$$$$.

I took a look at all the other wiring in the harness and surprisingly it all looks good with no funny jumps or anything else of that sort. I was guessing somewhere along the line the board went bad so they jumped it and either the voltage regulator went bad or is out of the mix completely.so when I had the key in the on position with the new fuel sending unit it was getting too much power and blew

Sound like it could be the case?

It sounds like they had it wired so that voltage was going directly to the sending unit, instead of through the gauge. The sending unit provides the ground (varies with float position) for the gauge.

Thanks for all the help guys! I'll order those parts and hopefully that takes care of everything!

........

If your fuel gauge is not getting power you can jumper it to the power output of the constant voltage regulator (CVR). I've done this on two 68-69 Torino circuit boards since they are impossible to find in good condition and the power is the outer line which always getting broken over time.

You'll need 1/2 of a 9V battery terminal receptacle (Home Depot or Radio Shack) spliced into a ring connector for the fuel gauge power. The 9v battery terminal can be cannibalized from an alarm clock or smoke alarm. Just trace the line from the CVR and it should go to one of the fuel gauge terminals on the board. Only connect the output of the CVR to the terminal. You must have 5V for the fuel gauge or bad things happen.

Sounds complex, but it's pretty easy. I'd also get a solid state CVR from CJPonyParts. It's a must have.

KR

Here's an amazon link of the part I'm talking about.

http://www.amazon.com/Pacific-Science-Supply-Battery-Connector/dp/B001F39728