fuel sending unit broken??
 

hello forum. i am driving a 1992 audi 80 1.6 gas.

i am trying to build a custom diagnostics tool, and i am stuck at the fuel level sensor... (i do not have a speedometer, or any fuel gauge)

the fuel pump/sender is reached, by a small hole, in the trunck. there you can see , a connector that is like this :

Attachment 104287

where the connectors 1,4 are the ones for the fuel pump.

so i suppose the 3,2 are for the fuel sending unit?? the thing is, that when i connect the DMM on those two connectors, i dont read any resistance at all... is the fuel sender broken? or am i doing something wrong??

That is the connector that goes into the chassis wiring. Two of the wires feed voltage to the fuel pump. The other two lead back to the instrument cluster.

You need to measure the other side of the connector (at the top of the fuel tank) to check for the fuel level sender resistance.

I'd bet big money that it is your Fuel sending unit that has a broken wire, like this:

<img src="http://i1030.photobucket.com/albums/y363/Hybrid_hatch/Instructional/IMG_2802.jpg">

You can see on the right hand side of the photo there is a wire, it should be connected to the frayed wire on the sending unit float. It is a VERY common failure.

MIKE: ofc i was talking about the side that is on the fuel pump, and not the disconected plug... :)

Hybrid: that is what i am thinking... so i think i will go and have it removed, to be sure!!

It is really really easy to remove. and i know many people have just taken new wire and re soldered the new wire in place of the old with good results.

naiccccccccc. very good idea!! i havent thought about it! this might save me some money :D i will see if it can be done tommorow!

yeah super easy if you have a soldering iron, here is a better picture:
<img src="http://i1109.photobucket.com/albums/h422/Paulgo253/LR-0218.jpg">

head to do the same thing to my :)

Hybrid hatch, thank you so much! this was exactly the problem ! and i fixed it by soldering a new piece of wire!! thank you very much!!!

Happy i could help, I think there are a LOT of us who have had the same problem. Glad to see you get your car working better and keeping it on the road!