NO power thru the leads mfor sending unit

[chuck hahn]

Buddies 82 GS 850G is the bike. Everything works except the PO had cut the wires and all the night time bulbs from the tach. I found the two lead going to the fuel gauge and when I use jumper wires then gauge goes up. Problem is there is no power going to the leads off the main harness.

So here is what I THINK will work. Find any switched hot wire and run that to one of the plugs at the harness area..and then run from there up to the hot wire going into the tach and to the gauge itself.Next run a wire from the ground wire of then gauge down to the other female plug at the harness. So basically I will be creating its own seperate hot loop via whatever switched hot wire i use, thus when the sending unit arm is moved up and down the gauge should respond accordingly.....right????

[tom203]

I played around with one of these 5 years ago- here's my henscrathing. Maybe it will help if you can see it!

[chuck hahn]

So..if I read this diagram right..the power comes off the fuse box, to the gauge, then the ground side is the one the sending unit is hooked in line with?? Anything else in the gauge loop that should also be working that I need to check out?? Looks like maybe the oil pressure light is in that same circuit??

EDIT:::

I see the horns are in the same loop as the gauge..yes?? well the horn button is missing from the switch housing. Should I check the wires inside the left side switch too..to be sure they are in the loop still? If they arent will that cause the no power at the regular spot where the sending unit plugs in?? I am unsure if both the oil pressure and the neutral lights were working but I will check them..looks like they are in the same loop also.

[chuck hahn]

I know this is an 80 diagram and the bike in ? is an 82..but same principles apply..right? I just hate when previous owners get the wire cutters out. Darn near ready to tell him to find an OEM harness and just start from zero on this thing.

[chuck hahn]

So heres what I am gonna try.

Find a switched hot wire and run that up to the gauge.
Run a gropund from the guage to another known gorund such as the ones for the turn signals.
Place the sending unit in one of the wires so when the sending unit arm moves, this SHOULD also actuate the gauge....sound right???

[jbird7262]

Chuck, I was wondering if that wiring diagram is the same as a 1980 GS750E, at least color wise for chasing wires. Would love to have staples print and laminate me one.

[chuck hahn]

Dont know. Someone started making colored wire diagrams a while back. Search colored diagrams maybe.

Set up the loop like I though would work and the gauge is functional again.

[Grimly]

The fuel gauge is getting a regulated voltage feed - be interesting to see what the output of the regulator is; it might be 12, 10, 7V. Without a regulated or stabilised voltage, the gauge could bounce around all over the shop with the tank's contents sloshing around, or simply read too high or low all the time.