- E-Type Forum -

Fuel gauge troubleshooting

Joe Golichnik
Wisconsin Jaguars Ltd. *

forum user since 2011-11-04

 

The fuel gauge recently stopped working on my 67 OTS. The low fuel lamp works, but the gauge always shows empty which would seem to indicate that the sender is functioning properly. Is there a way of testing the gauge?



Neenah, WI
Red 67 OTS, Black 67 OTS, Blue 66 FHC, Silver 00 XKR coupe, 60 MGA

Fuel gauge troubleshooting

Joseph S Boyce
Jaguar Association of New England *

forum user since 2011-04-04

 

Joe,

I've not actually tested one from a E-type, but typically these are coil with a moving contact that varies the resistance as the lever arm moves up and down. You should be able to measure the resistance with a multi meter. If it shows a short or an open circuit, the sender has failed.

Joseph Boyce
Lincoln, MA
66 E-type fhc

Fuel gauge troubleshooting

William Brady
Jaguar Owners Club, Inc. *

forum user since 2004-02-15

 

To test, disconnect the two coloured gauge wires, then with the ignition on ground the wires one at a time, ( do it right at the black ground wire on the sender) Check the gauge, one will be the low fuel indicator, the other will be the sender unit. If the gauge does not move then the problem is with the wiring/gauge if it goes to full the sender is the problem

Jaguar affectionado and etc.

Fuel gauge troubleshooting

Dave Goodson
Jaguar Drivers and Restorers Club of NWA *

forum user since 2008-04-29

 

Gauge wires on the sender unit. If reading empty, from my experience with my MK2, probably a sunk float.




Fuel gauge troubleshooting

Joe Golichnik
Wisconsin Jaguars Ltd. *

forum user since 2011-11-04

 

Thanks for the input. I tested the wires as suggested. Grounding one wire illuminated the low fuel light but grounding the other had no effect on the gauge. If a sunk float, as mentioned above, would grounding that wire still move the gauge (assuming no issue with wiring or gauge) or does this eliminate the sender as the culprit?

Neenah, WI
Red 67 OTS, Black 67 OTS, Blue 66 FHC, Silver 00 XKR coupe, 60 MGA

Fuel gauge troubleshooting

Dave Goodson
Jaguar Drivers and Restorers Club of NWA *

forum user since 2008-04-29

 

If no effect, the gauge proper is bad......but those are pretty robust. After eleventy million years, I guess anything can go bad. Now, drop the instrument face down, test light grounded, key on, what do you have on both sides of the gauge proper?


Fuel gauge troubleshooting

Dave Goodson
Jaguar Drivers and Restorers Club of NWA *

forum user since 2008-04-29

 

I should explain further. One, any power to the gauge shows there is power, which is good. Power on both sides, even dim on one, shows continuity through the gauge, also good.
Holding the test light, which is a load, on either side whilst twisting your neck to look at the gauge, check to see if the gauge moves.
If the gauge moves after oh, 15-20 seconds on one side, the gauge works (how accurate is another question for another time).
If that works, and you had no power on the non-warning-lamp side at the tank, I'd be looking for a parted or corroded connector in line.

Dave


Fuel gauge troubleshooting

Joe Golichnik
Wisconsin Jaguars Ltd. *

forum user since 2011-11-04

 

I had an opportunity to check the gauge as suggested. Test light lit brightly on right side connection (no movement on gauge), dimly lit on left side connection (gauge moved). The test light pulsed on and off on both sides.

Neenah, WI
Red 67 OTS, Black 67 OTS, Blue 66 FHC, Silver 00 XKR coupe, 60 MGA

Fuel gauge troubleshooting

Michael Eck
Jaguar Auto Group *

forum user since 2004-05-12

 

Hi Joe,

It sounds like the gauge is working. Now go to the sender and make the same test. One of the wires should also make the test light blink dimly, as it did at the gauge. If not, the wire is bad. If it blinks then the sender is bad. It could be a broken wire or simply a sunk float. They made the floats from used wine corks, you know.

www.jaguarclock.com
'51 XK120 OTS
'62 3.8 MK2 MOD
'72 SIII E-Type 2+2

Fuel gauge troubleshooting

Dave Goodson
Jaguar Drivers and Restorers Club of NWA *

forum user since 2008-04-29

 

Exactly what we were looking for. The pulsing is the instrument regulator (works like a turn signal flasher), the dim side is the side to the tank, the test light is a load, gauge moved, gauge good, wire parted somewhere.
Since you grounded both wires at the tank, the low fuel light lit, but the gauge did not move, probably not a sender or float, but to be certain, do the same test on the wires at the tank. If you get a dim flashing, hold it for 15-20 seconds (you won't hurt anything), drop the test light, scurry out from under and quick see if the gauge is off the peg.
If it is to any of those tests, wiring is good.
I'd maybe be looking also for a ground to the sender as an add-on, but that's just 45 years of old Flathead Fords under my belt.


Fuel gauge troubleshooting

Joe Golichnik
Wisconsin Jaguars Ltd. *

forum user since 2011-11-04

 

Resolution: Thanks to all for the assistance. After trying all of the tests listed above, I finally traced the issue to the wire running from the sender, to the connector under the lower left side of the dash. A jumper wire confirmed the problem and a new wire will be put in place after the driving season ends here in Wisconsin.

Neenah, WI
Red 67 OTS, Black 67 OTS, Blue 66 FHC, Silver 00 XKR coupe, 60 MGA

Fuel gauge troubleshooting

howard bollinger
Carolina Jaguar Club *

forum user since 2003-08-24

 

To all, A text book example of what great help you get from fellow members. Well done!

Howard Bollinger
1961 E-Type OTS #875864
JCNA June 2011 Calendar Car
1954 XK 120SE OTS #674495