fuel gauge problem

[scott]

i put in a 2nd tank. ran the wire from both sending units to a switch then to the gauge. was working, able to switch the gauge from l to r tank. the the oil pressure tube made contact with the back of the starter button and fried that wire all the way to the battery. while it was melting off the insulation it melted through the wires coming from my sending units. my truck has been converted to a neg earth. the problem is the fuel gauge is working backward. fill it up and it shows empty. cruise along and the needle climbs towards full. how do i reverse the polarity of the gauge?

[LaneRover]

My 109 does that to this day. I tried switching things around but the guage just went to zero. So I left it, thought of it as an added little 'if its stolen they won't get far' option.

I am not sure if you can reverse the polarity of the guage or if you would have to buy a later negative polarity guage. It may be an easy fix that I just haven't known about.

[scott]

it is a a bit of a novelty. i do have a new gauge. i'm wondering if it'll act the same way with less waving as i cruise

[rovertek]

i put in a 2nd tank. ran the wire from both sending units to a switch then to the gauge. was working, able to switch the gauge from l to r tank. the the oil pressure tube made contact with the back of the starter button and fried that wire all the way to the battery. while it was melting off the insulation it melted through the wires coming from my sending units. my truck has been converted to a neg earth. the problem is the fuel gauge is working backward. fill it up and it shows empty. cruise along and the needle climbs towards full. how do i reverse the polarity of the gauge? when you replaced the burned wires you did use the same guage copper wire as it originaly had diddn't you? first you need to check the guage by grounding the wire from the sender,(with the switch on) and the guage should move to the full position if it does not do that its the guage, if it does the sender should be checked with an ohm meter when you raise and lower the float the meter should go higher and lower,

[scott]

thanks, today was a brake day both axles. ran out of beer and interest before i could get to the gauge. maybe tomorrow. wire gage is the same, 12. i'll start with the grounding then the ohm meter. filled up the right tank and it reading 3/4 the left is under a 1/4 but reads full