My temperature gauge seems to be reading 100 degrees too hot. This started two days ago after I tried to get my stock gauge to work. Now, my new aftermarket gauge is reading too high. I tried replacing the temp sending unit, no luck. So, I thought that it may actually be the engine, so I replaced the thermostat, still reads 100 too hot. Then I did both of those things again. Then I tried another aftermarket gauge....same thing. When I turn the ignition on after the car has been sitting over night, the gauges read 160 as the baseline. I have absolutely no idea what I did. The only thing I can think of is that maybe I got a wire crossed when I was trying to get the stock gauge to work and somehow magnetized the block...is that even possible? I'm losing my mind over this one...

Thanks in advance.

-josh

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64 Dart 170 /6

Also, my stock temp gauge still doesn't work. I've got two of them and both just peg out to H as soon as the ignition is on...so it remains disconnected. No clue on that one either.

-josh

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64 Dart 170 /6

From my understanding it is a faulty instrument voltage limiter. 65 and earlier use a limited built into the fuel gauge, when it cooks, your gauges go to nuts. They either get the full 12 volts(like yours) and read high or they get no power and don't move at all (like mine).

This leaves you with two choices. 1 get the gauges rebuilt by someone that knows what they are doing. 2 go through and buy a voltage limited from another year, 1966 works, and read your wiring schematic and wire it in. its not too hard to do, my car has it, someday if I get the chance I'll pull the panel off again and take some pictures for everybody.

yeah, that was my assumption concerning the stock gauge (although the fuel gauge does work fine), but I'm still confused about the aftermarket gauge that's reading too high. I mean, it was working fine before I messed with the stocker.

-josh

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64 Dart 170 /6

Trying to think here, I'm no electrician but how is the aftermarket gauge wired in. Did you wire it independently from the other gauges or did you splice it in from the stock unit. What I'm thinking is if you wire it separetely we can eliminate the the voltage limiter.
caleb

The aftermarket gauge is wired seperately. Positive wire to a 12 volt source, ground, and then a wire straight to the sending unit. I'm totally confused.

-josh

Allright, I've got one shot left and then I'm out, this is more than i know. After I got the voltage limiter replaced I still had trouble, the wire for the temp sending unit was shorting against the block and running hot. After I found the break it was allright. Otherwise, I don't know what to say, try to repost and see if any body else shoots a line your way.
caleb

The gauges work of a "controlled return" circuit, basically the sending unit is controlling the amount of current going to ground.

The guage(s) will read high of peg if there is a short to ground. They will also read high if the positive side of the circuit has increased voltage.

Recheck all the wire and connections. Check the voltage coming into the gauge. Check the coolent temp, maybe the thermostat just stuck half closed and the engine really is running hotter.
DD

Put a meat thermometer in the radiator and verify the engine temp. Then hook up your aftermarket gauge without using any of the original wiring. That should get you a correct reading. If so, then you can look for problems with the original wiring.

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Chuck Rivers, Webmaster

This will cost you some money for another temperature gauge. Pick up a mechanical temp gauge and this should give you an accurate temp indication. Then you can troubleshoot your electrical problems without worrying whenther your motor is running hot or not. Just a thought

Make sure the gauge ground wire is clean and tight, and check your engine-to-battery negative cable and/or engine-to-chassis ground strap.

The only other problem I can think of with an electric gauge is as mentioned above, a short in the sending unit wire somewhere (check where it passes through the firewall).

-S/6

i have the same problem with my aftermarket gauge tops out at 300. I rehooked up my dash gauge and seems to be fine but i cant figures out whats wrong i looked at my amp gauge and seems to be running more on the plus side i read this could be a problem so how can i fix that?