Fuel Gauge past full

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Jtobe81

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Fuel Gauge reads past full. I tested the gauge it is good and new. new sending unit and tested with the gauge. works normal when hooked up with leads. tested the circuit board with leads to the sending unit and gauge works normal. checked ground.

I am lost think i have done everything.
 

Dmack

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3 o'clock means you have an open circuit, like a broken wire, unplugged, etc. 9 o'clock means it's grounded somewhere.
 

Jtobe81

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yeah i did the trouble shooting steps that i found on you tube from lmc, where you test the gauge using a battery and leads. the gauge and sending unit work normal when i have them hooked up with leads to a 12v battery. That was my last thought maybe a broken wire. looks like the wire is pink/red from the sending unit. trying to follow it back but cant find out where it goes into the cab.
 

Jtobe81

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I traced the wiring from the sending unit on the single tank on the drivers side, its a pink/wht wire that runs across the frame to a 6 point connector. previous owner converted to single tank. there is no selector valve. The harness is not connected to anything. looks like they didn't complete the wiring?
 

Jgonick

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6 point connector.
should be a pink wire (pnk-30) coming off connector- that is the wire that should run to your gauge.
Single tank set up has pnk-30 running directly to the tank.
You must be registered for see images attach
 

Jtobe81

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How do I bypass the old wiring from the second tank, and wire from the single tank sending unit to the gauge?
 

Jgonick

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How do I bypass the old wiring from the second tank, and wire from the single tank sending unit to the gauge?
If PNK-30 wire is there, just connect it to tank instead of PNK/WHT-930. There might even be the correct connector on PNK-30 (notice on diagram above-the little circle on the wire)

attachment shows location of PNK-30 on bulkhead- you could check to see if yours is there if you are not sure
 

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Jgonick

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You must be registered for see images attach
 

Jtobe81

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Here is some pics maybe give some idea. in picture one that connector that goes to nothing is the pink / wht wire they had connected to sending unit.
 

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Jgonick

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In theory- follow the pink wire (pnk-30) from 6 point connector- you should come across the same type of connector that is on the pnk/blk wire (the one you show in the attachment) - unplug it from the pnk wire running to 6 point connector and plug it into sender. - I believe it should reach the tank (hopefully)
 

Jtobe81

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Ok I found the connector you were talking about, disconnected it, was too short so i had to extend it. plugged it into the tank. good sign its not past full to the 3 oclock anymore. cant remember on these trucks, the tank is about 1/2 full maybe little more. when i turn key on it goes to about 1/2 then when shut off climbs back to full.

Thx for your help! making progress
 

Jtobe81

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weird now when i turn on the head lights the fuel gauge goes to 9 o'clock?
 

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