Stealth Instrument Voltage Regulator Fix

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devo
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Re: Stealth Instrument Voltage Regulator Fix

Post by devo » Sun Dec 04, 2016 11:07 am

AidanDawn2000 wrote:Awesome solution! @devo
So easy to build and it works great! Putting the links in was really helpful too.
Happy to have helped!

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sfdaugherty
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Re: Stealth Instrument Voltage Regulator Fix

Post by sfdaugherty » Tue Jun 12, 2018 2:27 pm

I finally took the time to build one of these. My original VR seemed to be accurate but occasionally it would just die and I had to reach under the dash and wiggle it to get it to work (I thought is was a grounding problem but it turned out not to be).

It was very easy to put this together and the fuel readings are rock solid. One problem I do have is that the fuel gauge registers about 1/8 low with a VERY full tank of fuel (I topped it off manually just to be sure it was full).

I have some questions - 1) Do the original VRs put out 8V or slightly more (I can test my stash to see what they register); 2) Should I adjust my sender unit to compensate for the discrepancy; 3) I'm not sure that I believe my temperature gauge now . . . is it also low?
69 2000 SRL311-10088
68 SR20DE SPL311-18735
68 2000 SRL311-01179
69 2000 SRL311-10485 (1/2 owner)
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Nissanman
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Re: Stealth Instrument Voltage Regulator Fix

Post by Nissanman » Tue Jun 12, 2018 8:28 pm

You should use an external temp. sensor such as a thermo couple to crosscheck with the reading on your temp. gauge.
The gauge is adjustable internally to make it more accurate.
If your Fuel gauge also reads low then you may be able to re-position the float by bending the float arm slightly.
Personally, I prefer a "pessimistic" fuel gauge but probably not that pessimistic ;)
Nissanman, just trying to help.
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msampsel
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Re: Stealth Instrument Voltage Regulator Fix

Post by msampsel » Tue Jun 19, 2018 12:53 pm

sfdaugherty wrote:
Tue Jun 12, 2018 2:27 pm
I finally took the time to build one of these. My original VR seemed to be accurate but occasionally it would just die and I had to reach under the dash and wiggle it to get it to work (I thought is was a grounding problem but it turned out not to be).

It was very easy to put this together and the fuel readings are rock solid. One problem I do have is that the fuel gauge registers about 1/8 low with a VERY full tank of fuel (I topped it off manually just to be sure it was full).

I have some questions - 1) Do the original VRs put out 8V or slightly more (I can test my stash to see what they register); 2) Should I adjust my sender unit to compensate for the discrepancy; 3) I'm not sure that I believe my temperature gauge now . . . is it also low?
not sure the precise voltage of the OEM mechanical gauge.

I built one with a 7808 (solid state device) and the output voltage was too low. When I used 7809 device the output voltage was 7.8 volts (which seemed good). So what is your output voltage of your new VREG? If it's around 7 volts instead of 8, it could be part of the issue.
The sender is pretty simple and if a full tank gets you to the minimum impedance (AKA 10 ohms resistance) not much else to do there.

As Nissanman said the gauge itself is adjustable.
And I stole the following from caraddict:

"The fuel gauge is adjustable from the back. It is a mechanical adjustment that can be made with a medium sized straight blade screwdriver. (One slot on the low end and one on the high end) Each adjustment does affect the other so it's easier if you can remove the sender and adjust the arm from full to empty while tweaking the gauge."
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sfdaugherty
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Re: Stealth Instrument Voltage Regulator Fix

Post by sfdaugherty » Tue Jun 19, 2018 2:22 pm

I'll do some more tests this weekend before I start trying to adjust the gauge (since it was correct prior to updating to the solid state upgrade).

Thanks for the tips.

Shannon
69 2000 SRL311-10088
68 SR20DE SPL311-18735
68 2000 SRL311-01179
69 2000 SRL311-10485 (1/2 owner)
68 1600 SPL311-20462 SOLD! After 41 years in the family