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How To Fix Your Nippon S' Temp And Fuel Gauge Voltage Regulator

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#1 Guess-Works.com


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Posted 20 January 2010 - 06:57 PM

Before i go on any further i would like to say a big thanks to DKLawson for the inspiration to do this

First task, a simple one, remove the clear plastic and the inner black face of the cluster so you left with this

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To make things a little easier and to avoid damage to the temp gauge, remove the 4 screws that i have circled red, this allows you to remove the fuel gauge which also holds the voltage stabiliser.

Then flip the cluster round, and remove screws 1 and 4, now this was a picture taken a few steps later hence why 3 screws are already gone.

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with the gauge removed, you then need to block the contact points marked, i used some electrical tape

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Now...i chose a 1 Amp fixed voltage regulator from maplins

Now before anyone moans..i only had 2 colours of wire so i numbered the pins, 1 is the input, 2 is the ground and 3 is the output

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Because of the proximity of each pin, and the fact im not realy any good at soldering smile.gif i used some electrical tape to isolate each terminal, and them wrapped all 3 together for neatness and to ensure they don't move/flex too much

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All you have to do now is add some ring terminals to the end of the wires, now its up to you where you mount it, DKLawson suggested moutning it onto the firewall to use it as a heat sink, but personally i didnt fancy having long wires reaching to the bulkhead, so i chose to buy a heatsink for my chip at maplins

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The ring terminals get screwed to the back of the cluster, 1 is the input, 2 is the output and 3 is the ground

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with all screws back in you should have a working pair of gauges running at a constant 10V with a deviation of +-0.05V
which is a hell of alot better than the smiths stabiliser going from approx 13.8V to 0V and back again

Now i mounted the chip with heatsink to the back of the cluster, please note i have used electrical tape as i misplaced my glue gun which i would have used if i hadnt of lost it, this is only a temporary fixing to stop it from flapping around

Also note i found it neccessary to bend the ring terminals as shown in the pictures, this i found to be neccessary or else the terminals would have came into contact with other PCB lines

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the chip and heatsink only cost me just shy of £2 together so this is not an expensive modification, i cannot comment on price of soldering iron, solder, wire and terminals as i have already had them and for some time so unfortunately cannot remember prices

the specific chip i used was maplins order code N38CA

If a MOD would be kind enough to make this a stuck thread or whatever the word is would they please do so as i have seen many to[pictures/threads now on gauges not reading right even though the senders are fine or new.

So this would be a help to many people i am sure

Big thanks to those who helped me with this

Please direct any questions regarding this FAQ to the Author Stormintrooper

Edited by Guess-Works.com, 20 January 2010 - 06:57 PM.

#2 Spider


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Posted 03 January 2019 - 06:55 PM

Thanks to Doug, John and Stormintrooper for this FAQ.


The Regulator referred to is a 10 Volt unit. It is generally known as an LM7810 and it may have some letters after this.


Maplins that were also referred to in the article have sadly closed their doors.


As one alternative supplier for these Regulators, you can get them from RS Components, though I'm sure there would be other suppliers




In addition to the Regulator, I would suggest a couple of small capacitors also be included, around 1 microfarad, with at least a 25 volt rating, these are usually a 'polarised' capacitor, so watch the connections. Connect one between the Input and Earth and the other between the Output and Earth, the closer to the Regulator, the better. These provide some 'basic' protection for minor voltage spikes.

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