Fuel gauge issue

[ducttape]

This is new to me as my old Series III either read full, or empty. My 67 Series IIA reads half full and works gradually towards empty. When I switch tanks, that one reads the same too.

Any ideas? Driving me crazy, spending $45 and seeing half a tank of gas.

T I A

David

[Whiterabbit]

Sounds like the sender maybe? Sticking,bad float or worn out.
I've got a SIII with L&R tanks and my gauge wouldn't read correctly until I replaced the voltage stabilizer behind the speedo.

[SafeAirOne]

Driving me crazy, spending $45 and seeing half a tank of gas.

Isn't that normal??--It's what I see every time I put die$el in my 109.


I had the same problem a long time ago (1/2 on the gauge= full tank). I'd recommend replacing the voltage stabilizer, since that and the gauge are the only significant shared items in the fuel indicating system between 2 tanks with bad readings.

[Partsman]

Better than what mine reads E=Full the gradually works it's way to F=Empty I got so frustrated, I opened the guage up and painted the two letters so the F looks like an E and the E looks like an F.

[LaneRover]

Better than what mine reads E=Full the gradually works it's way to F=Empty I got so frustrated, I opened the guage up and painted the two letters so the F looks like an E and the E looks like an F.

Mine does that because it used to be a positive ground and is now a negative ground. I figure that 'F' means Fill the tank. 'E' means Ever more miles to go.

I also like to tell myself that it is a theft deterrent - or should I say a deterrent to a thief keeping the vehicle.

[Jim-ME]

Just switch the wires and it will read correctly.
Jim

[Alaskan Rover]

Sender unit on a IIA is a two part system. A rod with float hangs down into tank...this rod might need to be re-bent to reflect reading full w/ a full tank and empty w/ empty tank. Easy access to sender unit on top of tank.

Other possibility might be the electro-sensor unit itself. This is a series of brass reeds (sort of looks like the reeds on the inside of a harmonica). A contact from the float rod runs up and down this series of reeds. The reeds are hooked up to electrical wires and the signal goes directly to fuel guage. Most likely your problem is here. I rebuilt this system of brass reeds and sensor unit myself on my Series IIA. That was 10 years ago of daily use...it's been working fine (knock on wood) ever since.

Once you get it apart it is actually not as complex a sensor unit as it would seem.

Good luck.

--

[LaneRover]

Just switch the wires and it will read correctly.
Jim

Not for me, I tried that. Switching the wires just pegged the gauge.

[Partsman]

Not for me, I tried that. Switching the wires just pegged the gauge.

Same here, when I inquired on the S2A forum, and posted pics, it turns out that mine has a mis-matched set old gauge, newer sending unit, at least that's what everyone over there is telling me. One of these days, I'll get around to replacing one or the other.

[ducttape]

Where is the electro sensor? In the tank, or on the fire wall?

Thx

Sender unit on a IIA is a two part system. A rod with float hangs down into tank...this rod might need to be re-bent to reflect reading full w/ a full tank and empty w/ empty tank. Easy access to sender unit on top of tank.

Other possibility might be the electro-sensor unit itself. This is a series of brass reeds (sort of looks like the reeds on the inside of a harmonica). A contact from the float rod runs up and down this series of reeds. The reeds are hooked up to electrical wires and the signal goes directly to fuel guage. Most likely your problem is here. I rebuilt this system of brass reeds and sensor unit myself on my Series IIA. That was 10 years ago of daily use...it's been working fine (knock on wood) ever since.

Once you get it apart it is actually not as complex a sensor unit as it would seem.

Good luck.

--

[mearstrae]

In the tank. Turn out the tank retainer ring and remove the float, rod and pick up together. It's not really a sensor it's a "Sweep Potentiometer" that is, as it sweeps, it changes resistance and reads on the gauge [kind of an ohm-meter]. Might just need a cleaning.

'95 R.R. Classic LWB
'76 Series III Hybrid 109
'70 Rover 3500S

[mearstrae]

Woops it posted twice... In the tank. Turn out the tank retainer ring and remove the float, rod and pick up together. It's not really a sensor it's a "Sweep Potentiometer" that is, as it sweeps, it changes resistance and reads on the gauge [kind of an ohm-meter]. Might just need a cleaning.

'95 R.R. Classic LWB
'76 Series III Hybrid 109
'70 Rover 3500S