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TR2/3/3A TR3 Erratic fuel gauge finally quits....testing?
- Thread starter karls59tr
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TexasKnucklehead
Jedi Knight
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Re: TR3 Erratic fuel gauge finally quits....testing?
A wire from the battery?
I'd start by using a volt meter to check for 12v on one of the fuel guages terminals, and ground on the other. If you want to see the guage move, dissconnect the side that is not connected to +12v (the sender side) and ground/open it (acting like the sending unit).
You probably have an open to the sending unit, or a bad ground at the sending unit, but it's nothing you can't track down with a cheap multimeter.
A wire from the battery?
I'd start by using a volt meter to check for 12v on one of the fuel guages terminals, and ground on the other. If you want to see the guage move, dissconnect the side that is not connected to +12v (the sender side) and ground/open it (acting like the sending unit).
You probably have an open to the sending unit, or a bad ground at the sending unit, but it's nothing you can't track down with a cheap multimeter.
MGTF1250Dave
Jedi Knight
Offline
Re: TR3 Erratic fuel gauge finally quits....testing?
Aloha Karl,
A 9V transistor radio battery connected to the fuel gauge is a safe and simple tester. The battery will supply enough power that should produce movement of the needle if the gauge is working, but not powerful enough to damage anything.
Here is a link to a very comprehensive article on how to test and calibrate the gauge:
https://mgaguru.com/mgtech/electric/fg_06.htm
You can build the test unit for about $25 (US) with parts from Radio Shack.
Aloha Karl,
A 9V transistor radio battery connected to the fuel gauge is a safe and simple tester. The battery will supply enough power that should produce movement of the needle if the gauge is working, but not powerful enough to damage anything.
Here is a link to a very comprehensive article on how to test and calibrate the gauge:
https://mgaguru.com/mgtech/electric/fg_06.htm
You can build the test unit for about $25 (US) with parts from Radio Shack.
martx-5
Yoda
Offline
Re: TR3 Erratic fuel gauge finally quits....testing?
I've calibrated several gauges for the Triumph club using the resistors. It works out to be very accurate if you have an original tank unit. I found that some of the aftermarket tank units don't have the same length of swing...usually the arm is shorter, and then you have to apply the fudge factor to get a decent approximation of tank contents.
I've calibrated several gauges for the Triumph club using the resistors. It works out to be very accurate if you have an original tank unit. I found that some of the aftermarket tank units don't have the same length of swing...usually the arm is shorter, and then you have to apply the fudge factor to get a decent approximation of tank contents.