Faulty Fuel Gauge

[wmrunyon]

I need some advice. i have a '91 Bravo and the right fuel indicator (in the panel) has been erratic for about 3 months. Now about half the time it is asleep against the left side peg; it might come alive for awhile indicating what it thinks as correct fuel levels. Then it will bounce around as if it has a short, then goes off line. Apparently the wiring diagram for these could wallpaper a small office, but my mechanic swears it is the indicator itself and not a connection, ground or anything with the fuel sending units in the tank.

The gauge, which he recommends replacing, is $850. Ouch. Is there a cheaper alternative? Please advice.

Thanks!  Bill

 

[KSMooniac]

There is some fairly simple trouble-shooting that can be done with the sending unit wiring, and that should be your first step.  I suspect your problem is there, and not the gauge. From a recent post by Don Maxwell on the email list:

******************

If I recall you have an F.The full reading says you have an open circuit. You
can check quickly by grounding the wire that goes to the center of the inboard
sender. If it goes to empty, the gage & wiring to it are OK. The inboard screws
are insulated and the inboard gage is grounded at the outboard sender. Wire goes
from gage to center of inboard sender. Inboard sender is insulated by gasket and
insulators at each screw. Wire leaves one of the mounting screws of the onboard
sender to the center of the outboard sender. Outboard sender is not insulated
and provides grounding for both senders. The two senders are in series. The
outboard sender is accessible thru an access panel under the wing. Ground the
center screw on the outboard sender and the gage should read empty.If it read
empty when you grounded the inboard sender but does not when you ground the
outboard sender then you have an open in the wire between the two senders.

Then he sent a quick correction:

Sorry, the wire goes from a mounting screw of the INBOARD sender to the center of the outboard sender.

*************************

I suspect the wiring is the same or nearly so for the Bravo, but you would have to check the wiring diagrams of course.  Before spending $850 you should have a go at the wires IMO.  Good luck!

[Parker_Woodruff]

Ugh...my fuel gauges have recently started getting rather whimsical in how much fuel they report, too.

[wmrunyon]

Scott,

Thanks for digging up D Maxwell's explanation. I may just fly over and let him figure it out. My mechanic states he is certain it is the gauge and i'm of the opinion it is wiring.

bill

[KSMooniac]

No problem Bill...he has just written that within the last week, and I had saved it to put in my "keeper" folder of useful tidbits.  It sure sounds like wiring to me, too.  Perhaps your mechanic doesn't relish doing the trouble shooting since you have to root around inside the interior/wings/tanks a bit...