gauge problem

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Apr 11, 2008
Hi, Finally got my stock 71fj running this weekend but a new issue showed up.The oil pressure, tempertaure, and gas gauge now go all the way to the right, not fast about30-40 seconds. I rewired the fj with a Quick way harness which was well labeled. I tried reversing the wires on the back of the oil gauge but no change. When I took the gauge cluster out thepower wir was on the left terminal of each gauge as viewed from the back and the sender wire was on the right. What did I do wring?
The gauges are not grounded good enough. On my 1980 the ground is a small metal tab near the temp gauge that pushes against the gauge cluster housing when it is all assembled. Poor (cheap) design, but after I cleaned the tab and the spot on the interior of the housing where it rubs with contact cleaner, and bent the tab out a little for more spring on it and put everything back together, my gauges operated correctly once again.
Hi, Thanks for the answer, I ran seperate grounds to everything else just missed the gauge pannel.
Hi, Checked for ground and it turns out I did run a ground to the gauge cluster but since I was there I ran a second to the housing not using one of the gauge screws but pop piveted to the case itself still the same problem gauges go to full right side after about 30-40 seconds, any other suggestions would be greatly appreciated.
Dogpen, the problem is in the interior of the gauge cluster, not the exterior grounding of the entire gauge cluster - the individual gauges themselves must be grounded to the interior of the tin cluster housing. The fuel and temp gauges are together on one circuit; there is a small metal tab on/near one or the other that is supposed to make contact with the tin outer cover when the whole thing is screwed together, but over 30+ years time it gets tarnished and/or no longer makes good mechanical contact with the housing. Take your gauge cluster apart and look carefully at the back of the gauges where the terminal posts stick out and you will find the grounding tab nearby. I looked for photos of it on mud but couldn't find any. Clean the tab and the spot on the tin cover where it touches of all oxidation and corrosion, carefully bend the tab out a little more so that it makes better sprung contact, and reassemble the gauge cluster.
Hi, Aftre taking the gauge panel apart I did not find any grounding clip however the gauges are made in such a way that they aren't allowed to touch any metal. The back side of each gauge post has a plastic guide that holds one fiber washer on each side insuring that it can't ground in this way. Each of the three gauges has a power wire and a signal wire, I thought the signal wire supplied the ground and the gauge registered the resistance. I have a spare panel and it is assembled the same way.It seems the ground is just for the lights on my 71.
The oil, fuel and gas gauges share power that is supplied by a voltage regulator that is built into one of the gauges (I can't remember which one). It sounds like you bypassed this voltage regulator, since deflection to the right indicates that they are sinking too much power (and not too little). Check where you attached the new power wire. It is not a ground problem because each gauge sender has a separate ground and if it was a bad ground, the gauge would not deflect and remain to the left side.
Pretty sure it's the fuel guage that has the VR.

Thanks for the reply. When I look at the picture of the gauge panel before I rewired the car there
was a yellow wire coming from the harness to the gas gauge and then connected to the other two gauges but all three were fed by the same wire.When I put the new harness in I used the wire labeled gauge power and wired it the same as the orginial. This is a early 71(NOV 70) and the gauges were wired seperately.
If the power was regulated from one of the gauges wouldn't it have to have one terminal in for power and another out for regulated power to the other gauges? Could I just put a resistor or the power feed wire to step it down? Any idea what kind of resistor I should use?
Thanks Jay
If the power was regulated from one of the gauges wouldn't it have to have one terminal in for power and another out for regulated power to the other gauges? Could I just put a resistor or the power feed wire to step it down? Any idea what kind of resistor I should use?
Thanks Jay

Yes. All of the gauges except the amp meter get something like 8-9V regulated.

A resistor is not a voltage regulator. Voltage will vary with current across a resistor. It is the change in current that makes the gauges swing.

You could use a zener diode circuit or an IC voltage regulator to control the voltage.
You don't need another one if the built in one is working and you have it wired properly.
Since it was working before you rewired it, it seems more likely that you have the power feed connected improperly.
You can get IC voltage regulators on line or at Radio Shack. I don't know what the proper voltage is. the stock one is adjustable.
Hi again, I used an ohm meter on three fule gauges and got 46.7-47.8 ohms. Then I took the front off of a fuel gauge and found two adjustments, one moves the needle position the other when hooked to the ohm meter or in series with 12v did not change any readings. I then tried to adjust one of the other
gauges from the back and it did not change the reading. I know this might seem simple to you but I am at a loss as to what may be causing this. I checked the factory diagram again and it is wired to the
diagram, any other suggestions?
The gauge housing needs a ground so that the VR will work, but if the panel lights work, it has a ground.

If that doesn't help, get a new meter panel.

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