fuel gauge voltage regulator

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Mainer311
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Re: fuel gauge voltage regulator

Post by Mainer311 » Thu Jan 29, 2015 3:16 pm

Curtis wrote:
Mainer311 wrote:Wow, that's pretty slick, and very cheap.
Based on the reviews about a 10% failure rate.
What do you expect for $7.70?
Jordan
1968 SPL311-21773. Needs paint and some upholstery.
2012 Xterra Pro-4X, 4" lift on 34's, UCA's, pre-runner bumper. Member of the New England Xterra Off-road club.
1971 PL521, Dragon green. Stock L16 w/ 4 speed, lowered 3".

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Curtis
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Re: fuel gauge voltage regulator

Post by Curtis » Thu Jan 29, 2015 3:55 pm

Mainer311 wrote:
Curtis wrote:
Mainer311 wrote:Wow, that's pretty slick, and very cheap.
Based on the reviews about a 10% failure rate.
What do you expect for $7.70?
Not much, but I'll bet the failure rate is even higher and people haven't gone back to comment. Looks to me like you'll still have to put it in something since it is just a board.
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andyroo
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Re: fuel gauge voltage regulator

Post by andyroo » Thu Jan 29, 2015 4:42 pm

Scroll up, I have one. :)

I think it works...I was having problems with my sending unit when I put it on and now my fuel tank is off the car so I can't 100% confirm. The temp gauge seemed to work so that's good.

But I tested the regulator with my voltmeter and it was spot on. No reason it shouldn't work. I may 3d print a case for it once I dial it in.

- Andrew
1968 Datsun 1600
2005 MINI Cooper S

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Mainer311
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Re: fuel gauge voltage regulator

Post by Mainer311 » Thu Jan 29, 2015 7:54 pm

Digikey has nice little injection molded ABS project boxes for cheap, but 3D printing your own is cooler.
Jordan
1968 SPL311-21773. Needs paint and some upholstery.
2012 Xterra Pro-4X, 4" lift on 34's, UCA's, pre-runner bumper. Member of the New England Xterra Off-road club.
1971 PL521, Dragon green. Stock L16 w/ 4 speed, lowered 3".

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Nissanman
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Re: fuel gauge voltage regulator

Post by Nissanman » Sat Jan 31, 2015 10:26 pm

Well, everybody else is doing it so I thought I would get into the act too :lol:
Image
I purchased a 3 terminal Voltage Regulator which outputs -8 Volts, suitable for the gauges.
Pins from the LHS are Ground, Input[-ve 12V] and Output[-ve 8V]
310120151562 (Large).jpg
It is placed in series with the 12V supply to the Fuel Gauge.
310120151563 (Large).jpg
The device is mounted on to a tiny piece of veroboard and housed in a gutted fluro tube starter :shock:
310120151561 (Large).jpg
Nice steady output voltage.

I haven't noticed a change from a series resistor to the VR since the Fuel Gauge is at mid scale atm.
Hopefully though, the E and F readings will be more accurate again than with the resistor.

For the POSITIVE GROUND cars the device is an LM7908, -8V output.
The equivalent for NEGATIVE GROUND cars is LM7808, +8V output.

All of a $1.45 at my local Electronics Store :wink:
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Nissanman, just trying to help.
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RBMann
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Re: fuel gauge voltage regulator

Post by RBMann » Sat May 02, 2015 5:46 pm

andyroo wrote:Scroll up, I have one. :)

I think it works...I was having problems with my sending unit when I put it on and now my fuel tank is off the car so I can't 100% confirm. The temp gauge seemed to work so that's good.

But I tested the regulator with my voltmeter and it was spot on. No reason it shouldn't work. I may 3d print a case for it once I dial it in.

- Andrew
How did you wire it into the system? Input + from battery, output + to gauges and both negatives to ground?
RBMann

mechanic on '69-1600(not mine)

andyroo
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Re: fuel gauge voltage regulator

Post by andyroo » Mon May 04, 2015 2:41 pm

That sounds about right...I'll let you know this weekend though.

I do still need to bench test my sending unit and fuel gauge.

- Andrew
1968 Datsun 1600
2005 MINI Cooper S

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RBMann
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Re: fuel gauge voltage regulator

Post by RBMann » Tue May 05, 2015 12:43 am

Okay, thanks.
RBMann

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beautyandplay
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Re: fuel gauge voltage regulator

Post by beautyandplay » Fri Jun 14, 2019 12:14 pm

Can someone tell me the correct in and out voltage for the in-line resistor mounted on the steering column of a 1966 model? My in is 14 v. and the out is 4 v. which is probably contributing to my incorrect fuel, temp and oil pressure readings. Thanks! Tom

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notoptoy
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Re: fuel gauge voltage regulator

Post by notoptoy » Fri Jun 14, 2019 12:46 pm

I believe you should have 12-14 in and 8V out.
"When all else fails, force prevails!" Ummm, we're gonna need a bigger hammer here.

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beautyandplay
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Re: fuel gauge voltage regulator

Post by beautyandplay » Fri Jun 14, 2019 1:23 pm

notoptoy wrote:
Fri Jun 14, 2019 12:46 pm
I believe you should have 12-14 in and 8V out.
Many thanks! Tom