[wannarace]

I just put in a set of autometer guages and have some questions. My fuel guage doesn't seem to be working right. It reads full and the tank is empty. I am using the stock 92 sending unit and am wondering what kind of voltage I should be getting from the sending unit.
I also put a T56 transmission in and am using the stock T56 speed sending unit to run the autometer speedometer. My directions are showing one of the two wires from the sending unit going to ground and the other going to the speedometer. Does it matter which wire is grounded and which is the signal wire?
THANKS...

 

[Ed Bleich]

If it is a stock GM fuel sender, it should measure between 0 and 90 ohms, depending on how full the tank is.

With regards to the speedo, I would say that it does matter which one is ground. I realize I not mush help on this.

Ed

 

[Judd]

HotRod, CHP and CarCraft have all done recent "how to's" in their mags. Check it out, maybe it will help.


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1969, X-44, Export Model, Hugger Orange, Std. Int., BC Rear(soon to be a BT 12 bolt), PDB, GMPP 350HO, M22 Supercase, SSM Lift Bars, AirGap, Holley 750, FlowMaster American Thunder Exhaust, FlowTech Headers

 

[Go69]

First problem-Fuel gauge-it sounds to me like you don't have the signal wire from the tank sending unit reaching the gauge. Or, if the signal wire is present, the ground for the actual gauge may be not connected well.

In regards to the VSS in your T-56, it does not matter which wire you ground. I just researched this last week and it appears that it makes no difference which wire you ground, and which wire you attach to the back of the A/M speedo. The VSS is simply a Hall-Effect switch that completes a circuit thereby generating a "pulse" that the speedo counts and then registers as MPH...

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1969 Camaro SS 350-383ci., T-56, 12 bolt, Eaton posi, 3.31 gears, 4 wheel disc, Deluxe black houndstooth interior, rear window defogger, tilt steering, console w/AutoMeter gauge package, center mntd. clock, Tach.

 

[wannarace]

THANKS, That's what I needed to know !!! I have found more wiring problems now to. I have also changed the motor and eliminated the computer so what I need to do is buy a painless wiring harness and clean it all up.
Thanks again for the help...

 

[dnult]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Go69:
The VSS is simply a Hall-Effect switch that completes a circuit thereby generating a "pulse" that the speedo counts and then registers as MPH...

<HR></BLOCKQUOTE>

Hall Effect switches are semiconductor devices and definately have bias. In other words I would expect it to work one way and not the other. Possible a circuit conditions the signal, but don't know for sure. Now a magnetic pulse sensor I could believe would not be polar.

-dnult

 

[Go69]

Dnult,
I would suspect that the VSS is simply a magnetic triggered device inside the tail shaft of the transmission as well. The quote I gave about the Hall-Effect switch is just that, a quote that I received from someone on the thirdgen.org site. I should have simply stated that it is a non-biased device and that either wire can be grounded to keep the confusion down..

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1969 Camaro SS 350-383ci., T-56, 12 bolt, Eaton posi, 3.31 gears, 4 wheel disc, Deluxe black houndstooth interior, rear window defogger, tilt steering, console w/AutoMeter gauge package, center mntd. clock, Tach.

 

[68sixspeed]

At least on machinery- hall effects are 3 wire devices, +,-, and signal which is either a + or - depending on if it's NPN or PNP (sinking or sourcing). If there are only 2 wires, it is likely that it is a magnetic reed switch. Hope that helps- Dan