Fuel gauge / sender - sending me batty

[gwkiwi]

* My 34 Californian has a fuel tank, wiring or sender issue and I need some help.

I have researched other links as well as sender issues on this site but mine seems a little weird.

It is a twin John Diesel with two seperate tanks and both gauges were reading accurately until a couple of weeks ago.

With battery on and no key turned on, both gauges read relatively accurately. When I turn the port key on the starboard fuel gauge pegs at full and the port gauge pegs at empty. With the starboard key turned on there is no issue.

I removed the port key and instrument assembly and all wiring looks good with no ground wire disconnected.

The gauges are in an area where it is almost impossible to remove or visually inmspect them but feeling up underneath the gauges and all wiring seems intact.

The fuel tank senders seem good and the fact that the tanks read accurate with ignition off seems to eliminate them.

Any help would be greatly appreciated - thanks in advance

Gerald*

 

[timjet]

Sounds like you got a real electrical problem to diagnose.

Doesn't sound like you have a gauge or sending unit problem, but it does sound like one or both gauges is grounding out when the port ignition is turned on.

Would running a temporary gnd wire from the gauge/sending unit directly to the battery be possible. Could be since you can't see the wires going to the gauge the gnd wire has chaffed or terminals corroded. Same thing for the pos terminals. Shouldn't be a big deal to rewire the positive to a new existing CB with new wire and see what happens. This should eliminate any connection with the ignition switch.

My gauges won't work without the stbd ignition switch on. With the stbd ignition sw on, power is supplied to a 3 way selector sw on the helm spring loaded to off. Momentarily selecting L or R allows power to flow to the respective gauge/sending unit.

I've replaced both sender units on my main tanks in the last year, one twice because the new one was bad. It ain't easy getting to them either.


-- Edited by timjet on Sunday 2nd of October 2011 07:44:17 PM