Fuel Guage possible reverse wiring

Moderators: Sluggo, Amskeptic

Post Reply
User avatar
highlandmurf
I'm New!
Location: Poughquag, NY
Status: Offline

Fuel Guage possible reverse wiring

Post by highlandmurf » Wed May 30, 2018 7:28 pm

Hi,
Recently had the engine out and attempted to adjust my fuel sender by +1/4 tank.
It had been reading about 5/8 when full. and zero'd out at about 3-4 gallons if I recall correctly.

Laid out an arch on the bench, and bent the arm about 25%.

Now it hangs up at way past full and does not budge. Drove it down to 1/4 tank and still hangs out up there.


Is it possible that I crossed the wires? Is that how it would behave with wires crossed?

If so, Could I cross the wires at the gauge to correct?

Working off of sender# 3. Boy do I hate this aftermarket crap!

Thanks
Joe
'76 Westy Marino Yellow

User avatar
Amskeptic
IAC "Help Desk"
IAC "Help Desk"
Status: Offline

Re: Fuel Guage possible reverse wiring

Post by Amskeptic » Fri Jun 01, 2018 12:45 am

highlandmurf wrote:
Wed May 30, 2018 7:28 pm
Hi,
Recently had the engine out and attempted to adjust my fuel sender by +1/4 tank.
It had been reading about 5/8 when full. and zero'd out at about 3-4 gallons if I recall correctly.

Laid out an arch on the bench, and bent the arm about 25%.

Now it hangs up at way past full and does not budge. Drove it down to 1/4 tank and still hangs out up there.


Is it possible that I crossed the wires? Is that how it would behave with wires crossed?

If so, Could I cross the wires at the gauge to correct?

Working off of sender# 3. Boy do I hate this aftermarket crap!

Thanks
Joe
Does the gauge sink down to below reserve when you shut off the ignition? If not, it is likely a problem in the gauge head. It has a devilishly delicate pivot wire that is attached to the needle, and it is pushed pulled by two bimetals.

For the record, 12 volts should never go to the gauge. It should only go the vibrator, which feeds moderated voltage to the gauge through a red wire. The gauge ground path is a brown with black tracer.
BobD - 78 Bus . . . 112,730 miles
Chloe - 70 bus . . . 217,593 miles
Naranja - 77 Westy . . . 142,970 miles
Pluck - 1973 Squareback . . . . . . 55,600 miles
Alexus - 91 Lexus LS400 . . . 96,675 miles

User avatar
highlandmurf
I'm New!
Location: Poughquag, NY
Status: Offline

Re: Fuel Guage possible reverse wiring

Post by highlandmurf » Sat Jun 16, 2018 5:55 am

Yup, it does go down when the key is off.

Note to self:

"I guess a 25% bend in the float arm does not equal a 25% correction in gauge reading- by a long shot!"

Just went from having an extremely inconvenient fuel gauge to having an entirely useless one!

Good thing I love my bus...
'76 Westy Marino Yellow

Post Reply