fuel gauge voltage regulator

Tech tips and how to's

Moderators: notoptoy, garth, S Allen

User avatar
peter
Roadsteraholic
Posts: 1187
Joined: Wed Apr 11, 2012 8:51 am
Location: Netherlands

Re: fuel gauge voltage regulator

Post by peter » Tue Jul 15, 2014 1:07 pm

I will try that too, but take it out first and test it with a power regulator to see how it respond with different voltages. tomorrow I let you now how it works. when it's good the output voltage must be constant.
Horsepower is how hard you hit the wall,torque is how far you take the wall with you.
Datsun Roadster '66 #7000 Sora Blue, restored 220 Hp and 340 Nm

User avatar
peter
Roadsteraholic
Posts: 1187
Joined: Wed Apr 11, 2012 8:51 am
Location: Netherlands

Re: fuel gauge voltage regulator

Post by peter » Wed Jul 16, 2014 6:03 am

So I checked it on a work bench and it was stable 7.98 volt.
I integrated it in the car with the ground and it looks much better now, I got an idea that it give some lower values as the mechanic on, but the mechanic one has sometimes fluctuation problems, and the electronic one is really steady. the only thing I have to watch is the heatsink, maybe it is to small, the temperature is about 40 degr celcius.
Horsepower is how hard you hit the wall,torque is how far you take the wall with you.
Datsun Roadster '66 #7000 Sora Blue, restored 220 Hp and 340 Nm

User avatar
Mainer311
Roadsteraholic
Posts: 868
Joined: Sat Jun 30, 2012 10:30 pm
Location: Methuen, MA, USA

Re: fuel gauge voltage regulator

Post by Mainer311 » Wed Jul 16, 2014 8:07 am

I think it will be fine. The gauges don't pull very much current, so the chip should not be working that hard. 40C sounds okay to me.
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".

User avatar
peter
Roadsteraholic
Posts: 1187
Joined: Wed Apr 11, 2012 8:51 am
Location: Netherlands

Re: fuel gauge voltage regulator

Post by peter » Wed Jul 16, 2014 8:31 am

When it works fine this summer, I will try to fit it in the original housing, and connect the chip to the metal housing.
Horsepower is how hard you hit the wall,torque is how far you take the wall with you.
Datsun Roadster '66 #7000 Sora Blue, restored 220 Hp and 340 Nm

andyroo
Roadster Fanatic
Posts: 244
Joined: Wed Aug 07, 2013 12:06 pm
Location: Baltimore, MD

Re: fuel gauge voltage regulator

Post by andyroo » Wed Sep 24, 2014 5:22 pm

Hi folks,

I need to fix/replace my voltage regulator. I may try the repair suggested here, but I was also doing some browsing for other options.

Early in the thread a home built option is discussed using a simple 12v to 8v regulator for dirt cheap. Probably available at Radioshack.
http://www.parts-express.com/7808--8v-v ... -220--7808" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
Image

Is it entirely necessary to wire in capacitors as shown in the schematics linked to earlier in the thread? The max v in for the 7808 regulator is like 35 volts, so I wouldn't think there be much trouble with the car battery that should be steady.

There is also the 7806 which outputs 6v. I've found larger (and more expensive) 7.5v output regulators which have a decent case.

I've also found a few adjustable regulators, though I have no clue how the adjustable part of that equation works.
http://www.amazon.com/DROK-Adjustable-R ... y_e_text_y" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
Image

Any thoughts on these easy and cheap options?

- Andy
1968 Datsun 1600
2005 MINI Cooper S

andyroo
Roadster Fanatic
Posts: 244
Joined: Wed Aug 07, 2013 12:06 pm
Location: Baltimore, MD

Re: fuel gauge voltage regulator

Post by andyroo » Wed Sep 24, 2014 5:30 pm

I think I might go with the adjustable one with the LED display. Seems like it has a knob to turn to adjust the output voltage and it looks like it would be easy to mount in a box.

- Andy
1968 Datsun 1600
2005 MINI Cooper S

User avatar
peter
Roadsteraholic
Posts: 1187
Joined: Wed Apr 11, 2012 8:51 am
Location: Netherlands

Re: fuel gauge voltage regulator

Post by peter » Thu Sep 25, 2014 1:41 am

I work now for a few months with the voltage regulator without problem, the only thing is that it shows the fuel gauge a little low at 8 volt.
Horsepower is how hard you hit the wall,torque is how far you take the wall with you.
Datsun Roadster '66 #7000 Sora Blue, restored 220 Hp and 340 Nm

andyroo
Roadster Fanatic
Posts: 244
Joined: Wed Aug 07, 2013 12:06 pm
Location: Baltimore, MD

Re: fuel gauge voltage regulator

Post by andyroo » Wed Oct 08, 2014 3:48 pm

I purchased the adjustable regulator with the LED screen. It's really neat. I've got it wired up and set to 7 volts out to the yellow wire but still nothing good on the fuel gauge...need to check the sending unit. Bummer. The temp gauge moves now, but my car wasn't getting very warm.

When it's all sorted I'll 3d print a case for it since I have access to that at work.

EDIT: the regulator is likely good and i just have other problems. i tested it with a voltmeter and it looks good.

- Andy
Last edited by andyroo on Thu Jan 29, 2015 4:44 pm, edited 1 time in total.
1968 Datsun 1600
2005 MINI Cooper S

KenSmart
Roadster Fanatic
Posts: 89
Joined: Thu May 22, 2008 7:04 am
Location: Sydney

Re: fuel gauge voltage regulator

Post by KenSmart » Wed Oct 08, 2014 6:34 pm

A bit late to the party but I did a solid state instrument regulator conversion about 16+ years ago inspired by Tom Walter.
My car is dismantled at the moment so I did some investigative surgery on the regulator.

Please excuse the crudeness of the setup. Mine is set to 8.1VDC I have used an LN317 adjustable reg.
Here it is running 12v in and 14v in showing 8.1 out. I ran it for 30min or so this morning and didn't seem to get hot, no load of course. As mentioned here the gauges shouldn't draw to much current. I'll hook up a dummy load and see how it goes, as with all regulators it will just turn off when it hits thermal shut down. Don't seem to be running a heat sink unless you count the spade terminal?

Also as mentioned here you can tweak the gauges a bit to get things right or in the ball park, from memory my fuel sender failed which added to my confusion. I have a new sender to go in the car when it goes back together.
20141009_092558s.jpg
20141009_092628s.jpg
Here is the outside and the inside of the can. The GND is provided by the black wire going to the terminal that is clamped by the can closing. There is a little vero board with the reg, two resistors, two caps and a diode
20141009_094516s.jpg
20141009_095211s.jpg
You do not have the required permissions to view the files attached to this post.

User avatar
Curtis
Site Supporter
Posts: 2541
Joined: Fri Jan 01, 2010 2:49 pm
Location: Des Moines, WA

Re: fuel gauge voltage regulator

Post by Curtis » Mon Jan 19, 2015 10:11 pm

Curtis wrote:With Nissan continuing to NLA our parts I asked Robert at Younker Nissan about the GVR. He told me that the 80’s & 90’s cars used them. Said they would be about $50 for those who don't want to build one.

After searching I found the part number and a picture. 3 wires, ground, 12v, yellow and gauge, blue.

24866-54A00

Image
So I finally got around to trying this in my car. The engine was cold so I did not get a temp reading. I compared it to the stock one and this one reads a bit lower on the fuel gauge. Might be you just need to calibrate the gauge to it. However, let me add that my gauge has never read correctly. Even with a full tank it has never read more just over half full.

Bottom line is it puts out 8 volts on the voltmeter and works. Needs to be tested with good gauge and sender unit.

I did a bench test of it as well. Since the fuel gauge I had out of the car was dead I hooked up the temp gauge to it and used the fuel sender to change the resistance. Temp gauge went up and down as I moved the sender to change the impedance.
66 stroker
67 basket case, the renewal has begun.

User avatar
Nissanman
Roadster Fanatic-Site Supporter
Posts: 2973
Joined: Mon Apr 16, 2007 8:07 pm
Location: Adelaide, South Australia
Model: 1500/1600
Year: Low Windshield-64-67.5

Re: fuel gauge voltage regulator

Post by Nissanman » Tue Jan 20, 2015 1:01 am

Just as a matter of interest, I'm currently calibrating a late model Fuel gauge to work in a '65 SP310.
The gauge expects to see a reduced voltage i.e. 8V but the '65 doesn't have the gauge Voltage Regulator.
So, I have introduced some series resistance to the gauge to give reasonable readings for a Full and Empty tank.
Still fine tuning the values, but it looks like ~65 ohm will be suitable to drop 4V and still give accurate readings.
I'd rather know when it is E rather than see it on F so that is what I am fine tuning ATM.
A $ or 2 for some 0.5W carbon film resistors :idea:
Nissanman, just trying to help.
1965 SP310 Engine No. G-93326 Car No. SP310-10817
http://nissanman.shutterfly.com/117
McQueen!
He's on the road again!

User avatar
Curtis
Site Supporter
Posts: 2541
Joined: Fri Jan 01, 2010 2:49 pm
Location: Des Moines, WA

Re: fuel gauge voltage regulator

Post by Curtis » Tue Jan 27, 2015 12:40 am

Further report on the newer Nissan regulator. I was testing the extra sender I bought on the car to see if the gauge worked correctly. It does so the sender in the car has some kind of problem.

I then hooked up the newer regulator and it works perfectly. Gauge goes to full, half and empty as it should. The gauge does take its time getting there though. Not sure if these gauges just move slow or not. When I first power it up the needle suddenly pops up and then moves along to full.
66 stroker
67 basket case, the renewal has begun.

User avatar
krismon
Roadster Fanatic
Posts: 199
Joined: Sat Aug 06, 2011 11:32 pm
Location: Las Vegas, NV

Re: fuel gauge voltage regulator

Post by krismon » Wed Jan 28, 2015 6:26 pm

anyone use one of these yet? There is a pot that you use to adjust the output voltage, and the display will tell you your input & output voltage.

Edit: they're $7.70 on amazon. http://www.amazon.com/DROK-Adjustable-S ... B00BYTEHQO" onclick="window.open(this.href);return false;
Image
1969 SPL311 twin DCOE KA24DE (Sunset)
2014 LEAF (PETROL)

User avatar
Mainer311
Roadsteraholic
Posts: 868
Joined: Sat Jun 30, 2012 10:30 pm
Location: Methuen, MA, USA

Re: fuel gauge voltage regulator

Post by Mainer311 » Thu Jan 29, 2015 7:41 am

Wow, that's pretty slick, and very cheap.
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".

User avatar
Curtis
Site Supporter
Posts: 2541
Joined: Fri Jan 01, 2010 2:49 pm
Location: Des Moines, WA

Re: fuel gauge voltage regulator

Post by Curtis » Thu Jan 29, 2015 9:22 am

Mainer311 wrote:Wow, that's pretty slick, and very cheap.
Based on the reviews about a 10% failure rate.
66 stroker
67 basket case, the renewal has begun.