# 1983 Nissan/Datsun 720 Pickup truck-gauge problem



## JoeMama (Dec 29, 2009)

I have a 1983 Nissan 720 Pickup and the fuel AND temp gauges don't seem to be working. I just bought this truck so I don't know too much about it. I checked the cluster and the gauges read about 45 ohms disconnected. 

From what I understand, the problem is the voltage limiter...where the $#*& is the voltage limiter and what does it look like? I do not see it on the back of the display console nor do I see it anywhere near the connectors for the console. 

I appreciate any help.

Thanks,
Ed
:wtf: (That's an appropriate smiley)
:newbie:


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## pulsar86 (Aug 13, 2009)

Try to find the instrument relay , should be near the fuse box. I think you might have a problem similar to one I had on my 1986 Pulsar. One relay handles both gauges, swap over with another one of the relays and see if the instruments work ok. I'm not sure on the 720 but I think the relay will be one of the ones above the fuse box on the interior kickpanel.


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## JoeMama (Dec 29, 2009)

pulsar86 said:


> Try to find the instrument relay , should be near the fuse box. I think you might have a problem similar to one I had on my 1986 Pulsar. One relay handles both gauges, swap over with another one of the relays and see if the instruments work ok. I'm not sure on the 720 but I think the relay will be one of the ones above the fuse box on the interior kickpanel.


I'll have to take a look at that once I get the console back in place. I do see two "relays"--one blue, one black. I'll check the pins and if they line up, I'll swap them and post the results.

Thanks,
Ed


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## JoeMama (Dec 29, 2009)

Well, I checked near the fuse panel and I see 2 relays. I cannot swap them as the pinout is different. I believe one controls the headlights but not sure about the other one.

Still cannot determine where the stupid IVR/voltage limiter is at. I tried to chase wires from the dash panel but it is too cold and snowy...lol Will have to check tomorrow.

I did find a square brass looking thing (looks like two of those together) with wires coming off them but can't see where they are going. It is about 6-8 inches above the fuse panel so a little difficult to get to.

If anyone knows from experience where it is, it would help. Otherwise, I will wait until daylight tomorrow and try to trace more wires.

Thanks


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## JoeMama (Dec 29, 2009)

Well, I think I fixed one problem but now have another.
I cleaned the contacts on the circuit panel with a #2 pencil's eraser and when I put it back together, the fuel shows 1/2 a tank :woowoo: (sounds about right). Don't know about the temp yet as NOW the truck won't start. Turned over a few times but because it is so cold, didn't start. Now, the starter won't engage. So, a NEW problem to resolve. But, it is -5c (23f) so it is a little cold to crawl around in the snow.

Once I get it going, it will run great again...lol


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## SPEEDO (Jun 9, 2003)

the volt reg is part of the fuel gauge....


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## JoeMama (Dec 29, 2009)

SPEEDO said:


> the volt reg is part of the fuel gauge....


I didn't see anything on the gas gauge or temp gauge when I had the dashboard pulled. I might pull it out again and check. After cleaning the contacts, the fuel gauge worked for about 10 min or so. Don't know about the temp gauge because the engine was cold and I couldn't get it started. I have fixed the starting problem (coil and/or wire from coil to distributor).

I found a "u-pull" parts place (just got a heater blower for $22 with 30 day warranty) and I might just get a new display. I know they have a gas gauge for $5. For that price, it might be worth just getting a new gas gauge and temp gauge. 

The Haynes color coating for the wires don't match what is running to the display cluster so I will have to trace wires. It's too cold to do that now. As long as I have my spare gas can full in the back, I won't worry too much until it warms up...lol

Thanks for the info. I appreciate all the help everyone is giving.


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## SPEEDO (Jun 9, 2003)

The volt reg is not separate.. its made into the fuel gauge... replace the fuel gauge


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## JoeMama (Dec 29, 2009)

SPEEDO said:


> The volt reg is not separate.. its made into the fuel gauge... replace the fuel gauge


I got a replacement from a bone-yard and I do see the volt reg on it. I hope it will get the temp gauge to start working also.

Thanks for all the help


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## JoeMama (Dec 29, 2009)

SPEEDO said:


> The volt reg is not separate.. its made into the fuel gauge... replace the fuel gauge


Fuel gauge is fixed :woowoo:

Temp gauge still not working--just checked. It is the sending unit. I grounded the wire and the gauge went to HOT so I will have to work on that now...lol

Thanks again for everyone's help.


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## BeeGuy (Jun 20, 2015)

JoeMama said:


> I have a 1983 Nissan 720 Pickup and the fuel AND temp gauges don't seem to be working. I just bought this truck so I don't know too much about it. I checked the cluster and the gauges read about 45 ohms disconnected.
> 
> From what I understand, the problem is the voltage limiter...where the $#*& is the voltage limiter and what does it look like? I do not see it on the back of the display console nor do I see it anywhere near the connectors for the console.
> 
> ...


When Fuel and temp gauges go out together in the Nissan 720 PU (best vehicle ever built) the fix is very simple. One of the electrical plugs in the back aren't making good contact. Pull out the cluster and clean all the contacting surfaces and gently increase the pressure by bending out the contacts on the plugs just slightly so to not weaken them. that's it works like a charm. I've had the same problem with 2 of my 720s.
Enjoy that truck, it's a good one.


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