Fuel Gage Problem

[fizley]

I need some technical advise from people who routinely work on Vintage Chargers.  I have a Factory '68 Charger (440 Automatic) and have an intermittent problem with the fuel gage.  Upon startup the gage will properly read the fuel level in the tank (i.e 1/2, full tank, 1/4 ect.)  After about a mile or two of driving the gage suddenly drops to empty and after several more miles of driving the gage will starting reading the fuel level properly. This is an on and off problem.  At first I suspected a short between the fuel sending unit and the gage and inspected the wiring. The wiring is in very good condition. Next I pulled the fuel sending unit and replaced thinking the float (or sending unit) was going bad.  When that did not fix the problem I replaced all the wiring in-between the fuel sending unit and gage and STILL have the same problem.  I am about to pull the gage cluster and send it in for full re-build (as it is the original factor Tic O Tac), but before I do that thought I should see if anyone here has any suggestions? Thanks

[Dans 68]

What you are describing is caused by a lack of a ground in the circuit. The gauge cluster needs to be properly and securely bolted to the dash frame to achieve the ground. If it is not tight then you'll get what you got. Some people actually connect a ground wire from the dash to the frame to get a good ground.

And welcome to the site!

Dan

[Dino]

Welcome!

I'll bet you it's the connector pins on the board.  They can make intermittent contact even when they appear snug.  My circuit board looked great but I would still have a few issues. I decided to solder each pin to the board to make sure they were secure and I have not had an issue since.  Test continuity before you solder it and wiggle each pin to see if power cuts out.

While you have the board out, replace the stock voltage limiter with a solid state RTE unit if you haven't yet.  It looks stock and you can even keep the condensor for looks.

[fy469rtse]

look up charger speciality's
new circuit board with voltage reduction , electronically built in , cures the pins and voltage problem ,
board will be bad, any thing you do to old board will be just a band aid fix,
i would also check the earth strap to tank ,

[fizley]

Thanks, for the responses.  As far Dan's suggestion for the ground.  I moved the ground to the Frame when I re-wired.  I check the pins and might just purchase the upgrade from Charger Specialities.  Appreciate the info!

[A383Wing]

could be a bad tank ground as well....is the fuel sender line ground strap in place?

[PlainfieldCharger]

could be a bad tank ground as well....is the fuel sender line ground strap in place?

I agree! I would start here...