What does this connect to?

[Guest]

I bought this gs1100 last summer and the fuel gauge has never worked. Yesterday I noticed what looks like a vacuum port that is disconnected under the fuel tank. I wonder if this is why my gauge isn't working. What do I connect this to?

[Highway_Glider]

Hi bille.

That's a "Case drain".

It's there in case the seal on the gauge should fail. It will catch the gasoline and drain it to the ground and avoid a possible fire.

Fit a rubber hose on it and feed it down through the frame.

[cowboyup3371]

That is an overflow from the gauge; that wiring hanging loose needs to be connected to the wires coming out of the harness for the gauge. If that's not working, you may need to swap out the sensor in the tank.

[mike_of_bbg]

That's a vent in case the gauge starts leaking. There used to be a hose which would deposit leaking fuel back behind the motor instead of right on top of it. It would not be the reason your fuel gauge is not working.

You might want to have a look at Mr. Basscliff's site. There's a doc on there about repairing the fuel sender unit.

http://members.dslextreme.com/users/bikecliff/

http://members.dslextreme.com/users/bikecliff/images/GSfuelguagesendunitrepair_by_mr_jethro.pdf

[chuck hahn]

To test the gauge in the instrument cluster before putting the tank on, take a wire and jump the two wires coming off the wiring harness and turn on the key. If the gauge works the needle will rise to the full level. If it doesnt move its obviously broke. Test this BEFORE putting the tank on to be sure. If it doesnt work when you set the tank on then youll know the sending unit in the tank needs attention. Yes they ARE repairable but you have to,be super super careful not to break the fine wire that connects to the waffle board.

To test the sending unit without mounting the tank.........once youve verififed the gauge works by using the jumper wire, hook the tank wires up to the harness and simply turn the tank up side down. The float will go to the top of the tank like when full of gas. If it moves the gauge youre good to go.

[sealpup]

Thanks Chuck, you've helped out two us today with one post....my 1000S fuel gauge has never worked and I figured it was most likely the gauge rather than the sender unit. However I removed the sender from the tank and took the cover off it to find a poor and intermittent contact against the resistive wire. That is now fixed (or at least better), and after your trying your test method above my gauge tested O.K. Happy Days!

As an aside, my oil temp gauge is also not working (stuck on about 90 degrees C). Given that the oil temp sensor is also a resistive device, will shorting the wire to ground drive the gauge to full scale deflection? I thought I'd ask before I risk doing some damage.

Thanks.

[chuck hahn]

Yes it does seem a possibility. Where does it read with the wire disconnected??

[sealpup]

Not so lucky this time - gauge still reads 90 with wire disconnected, and also 90 with the wire shorted to ground. I haven't measured the resistance of the temperature sender, but my testing proved that I at least have a problem with the wiring or the gauge.

Thanks for the advice Chuck.

[chuck hahn]

Tap gently on the side of the instrument cluster on the gauge side to see if the needle is stuck and falls with the wire off.