Fuel gauge question on a 67 wildcat

[snorat]

Happy Holidays all,

Yesterday I received my sending unit back from Tri Starr for my 67 wildcat and they did a great job with excellent turn around. I tested the sending unit with an Ohm meter and its 90 ohms when full and 1.5 when empty. The problem is when I hook it up to the gauge it only reads 1/2 full when the float is in the highest position and when it's in the lowest position it reads well below empty like the gauge is out of calibration. Is there any adjustment i can do to better align the gauge with the sending unit ?

thanks in advance

Kevin

[NTX5467]

Kind of sounds like if they replaced the "resistance board" with a new one, it doesn't have enough resistance for what the gauge needs to be in correct calibration. A possible "fix" might be to determine what resistance there is when the gauge is at "E" and then use the difference between that and the lowest valve to use to find a resistor which you might add to the gauge wiring between the sending unit and the gauge. I suspect that adding that extra resistance into the mix might compensate and get the instrument panel gauge to read more correctly.

Many OEM "special tool" "electric gauge checkers" only had "E", "M", and "F" notations for the (obviously) variable resistor "inside the box". IF you might find those particular values, then you might know a little closer as to what additional resistance might need to be added to the circuit.

Of course, you might need to run your issue by the rebuilder and see what their thoughts might be. Plus, if you might have an "original" unit for comparison, that might be good, too.

Just some thoughts,

NTX5467

[snorat]

thanks for the reply NTX5467,

I was thinking of heading up to radio shack and getting a few resistors of different values and giving it a shot. First I'm going to verify that all the Dash wiring is intact and ensure that all the grounds are properly attached. After taking it out for a spin today the gauge seems to be working normally other than the incorrect position of the needle.

Will keep you posted on my resistor experiment

thanks again

Kevin

[snorat]

Gauge issue is now solved.... In ended up being the gauge itself . First I bypassed the existing wiring, then cleaned all the contacts on the main connector at the cluster and finally removed the gauge itself cleaned the contacts and re-installed. In the beginning the gauge would read 1/2 full when the tank was full, (had 85 ohms to the gauge from the sender). Then the gauge eventually stopped reading entirely and would drop to dead empty as soon as you world turn on the key. I was lucky enough to find a nos gauge on ebay but was a little worried after it arrived because if you compared ohm readings between the new gauge and the old gauge they were the same. The only real difference was when i gently moved the needle on the new gauge with my finger it seemed to be tighter than the bad gauge the needle would move some a bit just by shaking it and offered little or no resistance when moving the needle with my finger.

Figured I'd pass along my findings just in case someone is having a similar issue

thanks