Allen,
Testing you fuel guage, senders, and selector switch is easier than it
seems.
Fil the tanks about 1/2 full of fuel. Since both tanks fhare fuel at
that level, they should read the same if both senders are working
properly.
Stick your head under the driver side of the coach about a foot or so
behind the front wheel. Search for a light brown and a light brown with
whit streamer wire. Each wire goes to a fuel sender, I can't remember
which is which- follow the wire to each tank.
Turn on you ignition and observe the guage on main and aux. switch
settings. Go under and cut say the light brown wire at a point where it
will be easy to reattach. In one switch position the guage should read
"E". Now, strip back the insulation on the cut wire heading foreward
and ground it to the chassis. Your guage should peg full. If it does,
your guage and switch are OK in that switch setting. If nothing
happens, you will have to access the light brown wire at the switch
inside the dash and bypass the switch there, if it now pegs, your switch
needs to be taken apart and cleaned. Perform the same test on the light
brown with white streamer wire to check the other circuits performance.
Now, reconnect the wires temporarilly. Do you have a 1/2 full reading?
If not you, will probobly will need to drop the tank to check the sender
movement. It may be a bad ground to the sender. Eather way, you will
need to drop the tank to check ground or sender output. I had one
sender that the sender wire broke at the sender, I still had to drop the
tank to find it.
If you decide to drop the tank, I would strongly suggest to replace both
senders and ALL of the vent, feed, and take off lineson the tanks. You
only want to do this once! Golby has a great replacement fuel sender,
you can call them at 1-800-872-1462. Give me a call & I'll tell you
about the hose sizes you will need at: 1-877-275-4462.
Good luck
Ji Bounds
www.gmccoop.com
