Gas Gauge Not Working

[mjones1700]

I hope that this is my last technical question. My gas gauge was working except sluggish (never reaching F even when very full and seeming to bottom out at 1/4 tank and never getting to E). So, during my major restoration I took the tank off, had it sand blasted and powder coated. I replaced the sending unit. The wire lead is securely attached to the sending unit, but the gauge is not responding even to a full tank. The rest of the gauges are fine.

Now I have one theory and see if this makes sense. With one lead wire running to the gauge that implies the tank must need to be grounded. Is it possible that the powder coating (plastic non-conductor I would assume) is insulating the tank (plus the rubber washers at the four holding bolts) so it is not getting grounded? Before I blow things up, I wanted to ask if it would it be reasonable to run a ground line to a bare metal spot on the tank to see if that corrects it? Thanks in advance.

[LaneRover]

My '66 88 has a ground wire running from one of the screws that holds the sender in place to the seat box. To the frame would probably be better. But I think a ground would be a great place to start.

[artpeck]

I had the same issue that you are experiencing and ran a ground to the seat box and it works great. Try that first.

[siii8873]

could also be the voltage stabilizer

[Partsman]

Mine has a ground from one of the screws on the sending unit to the chassis.

[mjones1700]

Thanks. I will try the ground to the sending unit screw.

[mjones1700]

Crap. Created a wonderful ground from the sending unit to the frame. Didn't work. Now I have to start this long process of trouble shooting.

[derekchace]

Ive owned 4 series and not one has ever had a working fuel gauge. I would ever trust a series gauge. I just go with the extra 5gal Jerry can method.

[SafeAirOne]

Ive owned 4 series and not one has ever had a working fuel gauge. I would ever trust a series gauge. I just go with the extra 5gal Jerry can method.

I'm gonna go out on a limb here and guess that none of your rovers had diesel engines...

[artpeck]

Assume you have made sure it is a good ground. Also does your send have one or two places to attach the wire as my replacement had two one of which is the warning light I believe if I recall correctly. Working back from that it could be the voltage regulator which is the next place in the circuit as well as the connection to the gauge itself.

[jcutler]

had this problem with my MGB. I'm willing to bet a beer it's the voltage stabilizer.

[mjones1700]

I've checked and rechecked the connections to the gauge (inside the dash) and they seem fine.

Dumb question but I can't remember where the regulator is located. Inside the dash? On the firewall in the engine comp? Do you simply replace it? I see that our host no longer carries them so what do I replace it with?

I'm going to take the sending unit out and mess with it and try to directly wire it to the gauge and start from there.

I'm about to the Jerry can position.

BTW, my favorite is Alaskan Amber.

[derekchace]

I've owned a bunch of Diesel defender all there gauges worked. All my series where petrol non of them worked.

[Broadstone]

Whenever I have an electrical fault I always run a wire from the neg. terminal on the battery to whatever I need to test. I feel this is a known good ground and cuts to the chase and avoids wasting some time. Remove the sending unit, ground the sending unit cover and hook up the wire then move the arm and see if you get readings. The wires inside the sending unit which read resistance are very fragile and can break causing the gauge to not work, I had that problem. Hope you figure it out.

[siiirhd88]

Early trucks don't have an instrument voltage stabilizer, but anything after 1965 or so, and all of the negative ground trucks should have one. The voltage stabilzer supplies a nominal 10 volts to the fuel gauge and electric temp gauge, but the actual voltage varies greatly at an average of 10 volts. The voltage stabilizer is normally mounted to the rear side of the speedometer or dual gauge, or is mounted to the bulkhead behind the gauge panel. The gauge circuit usually has a dark green wire (fused power with the ignition switch 'on') supplying 12 volts to the voltage stabilizer. The output from the satbilizer is a light green or light green with dark green tracer wire that supplies both the fuel gauge and the electric temp gauge. The other gauge terminal goes to the sender, which will be a dark green and black tracer wire to the fuel sender and a light green with brown tracer or dark green with brown tracer wire to the temp sender. The sender's function is to vary the resistance to ground to change the gauge reading, with a really good ground for a full tank or high coolant temp. If the problem is the sender or a poor sender ground, removing the wire from the sender and holding the wire end to a known good ground should peg the gauge upscale. If the gauge does not respond, you need to check the power to the stabilizer, to the gauge, and from the gauge to the sender. If the gauge pegs upscale, the problem could be a bad sender or poor sender or tank ground.

Bob

'02 DII SE7 Kalahari
'02 DII SD
'97 RR Vitesse
'80 SIII 109
'75 SIII 88 V8
'68 SIIA 109 V8