68 satellite instument cluster new problem (WOW)

[PUNKN8R]

Ok I purchased car with fuel gauge not functioning so previous owner had another cluster to go with car. So after a few days of swearing, cuts and bruises. I removed cluster installed different fuel gauge and alt. gauge reassembled and now fuel gauge sorta works (not sure how much fuel is in tank) it shows 1/4 tank and after running car a few minutes the gauge goes up a little more but upon further investigation when I flick left turn signal on the fuel gauge will slowly begin to rise towards full shut sig. off returns to 1/4. Upon more investigation when I turn emergency flasher on it will begin to rise towards full (faster) as well shut off and returns to 1/4 but with headlights on I push on dimmer sw. the left turn signal indicator in cluster will come on and the fuel gauge will rise to full even faster than signals shut off and as well will return 1/4.

STUMPED!

Am I missing a ground I know that if power lead to sending unit is grounded it will also move to gauge to full (fast). I have tried a battery to body ground no difference.


Is there a instrument panel ground I might have have missed I do not remember un hooking any.

Dimmer sw seems to be grounded as well.

Any help will be deeply appreciated THANX !!!

 

[Budnicks]

the fuel line should have a "clipped on" ground strap between the steel fuel lines & the sending unit, because it has a rubber hose connection, that's where the sending unit gets it's ground, the gauge panel & circuit board itself, grounds thru the upper dash gauge mounting screws on the top, if I remember correctly, "I think anyway", I would have to look, so don't quote me on that...

 

[PUNKN8R]

the ground strap is gone so it now has a 12 ga. wire hose clamp to sending unit then to ground. Hey Budnicks if take a jumper wire touch to dash panel then ground problem might be dash grounding ???? Thanx for reply !!

 

[Budnicks]

the ground strap is gone so it now has a 12 ga. wire hose clamp to sending unit then to ground. Hey Budnicks if take a jumper wire touch to dash panel then ground problem might be dash grounding ???? Thanx for reply !!

I hope it helps, hopefully the circuit board isn't bad, I guess/assume you already did/replace the Voltage limiter too, sometimes you need to clean the connections & put some dielectric grease on them too, just to get proper contact....

 

[PUNKN8R]

Still not sure voltage limiter bench tested fine everything else works fine but when put headlights on high beam turn left signal on dash lights up and gas gauge goes towards full tank.
I removed left bulb from dash, gas gauge went to 1/2 full, checked to see if dash was grounded and it is. I also noticed that left dash signal is a lot dimmer than right signal (in dash)even when used by itself. When I had dash out circuit board seemed ok no breaks in diagram. all lights work on dash board. (no high beam indicator at all). seems like a ground issue to me but not sure where to check next ??

 

[PUNKN8R]

just a thought should the steering column have its own ground or is that through the harness ??? 2nd thought can the emerghency flasher have a short in it ??
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[ws27]

Look on the spare board, try to trace the voltage limiter circuit and the signal indicator circuits. They probably share the same ground path on the board, the whole board grounds with the screws to the dash. The steering column should have a ground wire with a ring that goes to one of the four bolts that hold the column to the dash, but that shouldn't affect the gas guage.