[evilmcd]

Hi everyone,

The fuel gage on my 1970 Opel GT 1900 is not working. Any tips on figuring out the problem before I run amok and do something stupid? I assume the gage is connected to a float type sensor valve in the tank...

Thanks for the help

 

[Matt M240Z]

On the gas tank in the back, there is one wire that comes off of a circular looking device. That device is your fuel guage sending unit. Chances are, your sending unit (the part within the tank) has rusted and no longer works. But, to figure out if your guage still works, take the wire off of the sending unit, turn the key on, then take the wire and scratch it onto something metal on the car (throught the paint). If your guage is functioning, it should ground out and the needle should go all of the way to one side.

 

[baz]

hi sean most of the gauge problems are down to connection problems or the sender unit having earth problems , if you use the search engine with "sender tank and gas "you will find all you need about where to look and what to look for

 

[lewdawg]

I have similiar problems with my gas gauge as well. It only works when it wants to. Haven't taken the time to trouble shoot too much but have aquired three other sending units; all of which I tried and all of them don't work at all. I do know Opel GT Source repairs them and I will be sending them my three spare units to get as many of them overhauled as possible. I have noticed my temp gage going a little spastic here lately as well and was wondering if the gas gage and temp gage share a common ground. If it's not your sending unit then there are plenty of spare gages out there on e-bay or other Opelers. My money is on the sending unit. Good luck and let us know what you find.

 

[evilmcd]

Fuel Gage Issue Thanks

Many Thanks for the fuel gage advice - this was exactly what I was looking for!

 

[bear]

Lewdawg, you're right, all the instruments, in fact the entire instrument panel share the same ground bus on the back case of the speedometer. The main ground wire for that bus is on the fuse panel mounting stud. Double check that stud to be sure the ground wire is clean and tight. HTH.

 

[Jeff Pozorski]

Does the same common ground apply for Manta gauges? I put a tach in my Manta this past weekend and went for a ride. The tach worked great. I noticed, however, that at the very end of the ride, about 15 miles, my fuel guage started dropping to empty from a 1/2 tank or so. The needle went all the way past empty and stayed there. The entire time was probably 30 seconds to reach that point, so it wasn't a sudden "jump" to below empty. I assume a bad ground but would appreciate any other imput other Manta owners may have.

 

[Turbo X]

I have similiar problems with my gas gage as well. It only works when it wants to. Haven't taken the time to trouble shoot too much but have aquired three other sending units; all of which I tried and all of them don't work at all. I do know Opel GT Source repairs them and I will be sending them my three spare units to get as many of them overhauled as possible. I have noticed my temp gage going a little spastic here lately as well and was wondering if the gas gage and temp gage share a common ground. If it's not your sending unit then there are plenty of spare gages out there on e-bay or other Opelers. My money is on the sending unit. Good luck and let us know what you find.

Question?, did you check the units out with a volt ohm meter? it should read about a 90 to 100 ohm's when the float is to the top. and check the red plug connector for good connection, the fuel and temp use the same plug, you can spray wd40 on it, helps cleans the spades and lube's it..

 

[ben]

look what i found

gas sending unit
out of a vw
karmann ghia
cool wonder if it will work in a gt

 

[ungermm]

Ben, What are the measurements? The shaft looks a little short. My GT unit has a 9 1/2" shaft. A shorter shaft, if every thin else works or fits, would give you a premature empty reading. Jerry

 

[Gordy]

I had a 68 Kadett fast back that the fuel guage was erratic on and it was the ground wire back by the tank. Cleaned the connection up and it worked like a charm.i