Fuel Sender not working Options

[john77]

Hi

I'm the proud new owner of a 73 914/6 conversion, with a handful of minor electrical gremlins that I need to track down - so firstly, hello. And secondly, HELP!

My knowledge of car electrics is somewhere between idiot and novice, so please bear with me. The OEM fuel sender gauge has been swapped out for a 911 oil temp/pressure gauge and an aftermarket fuel sender mounted on the dash. The needle raises about 4mm when the ignition is switched on, but won't go any further no matter the level of fuel in the tank.

I removed the sender unit from the gas tank and the float isn't stuck (I have no idea how to check the sender internal circuitry). Then I checked the voltage at the positive pin of the sender and it's only reading 5.5V.

I have a Haynes manual in the mail, and am struggling to read the wiring diagrams on Pelican because, unless I'm missing something, none of them appear to have key of what each of the numbered components are. So I thought I'd seek help here because maybe the cause is something really obvious and, well, I'm impatient. (IMG:style_emoticons/default/smile.gif)

Thanks
John