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removing thermocouple from gauge


tcslr

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The thermocouple is not reading in my Chrysler. Clearly, I see how to remove it from the block. Short of unscrewing the entire gauge from the dash, how is the lead removed? see the attached photo. I tried to loosen it with my fingers but it only moves a small amount. I don't want to jam or break anything.

And any good suggestions for someone to repair? Thank you. Tom

post-72842-143142115316_thumb.jpg

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It is not meant to be removed. A new gauge from the car maker would have come assembled that way. There are gauge restoration places that can repair these.

Try google for temprature gauge restoration, etc

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There is a way to repair the temp gauge, (it is not easy)

1. You will need to buy a new aftermarket gauge that will fit your engine.

2. Put the bulb into something like dry ice.

3. Cut both tubes close to the gauge and solder the new tube on while the bulb is still subject to extreme cold.

The hardest part is not plugging the tube with solder.

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There is a way to repair the temp gauge, (it is not easy)

1. You will need to buy a new aftermarket gauge that will fit your engine.

2. Put the bulb into something like dry ice.

3. Cut both tubes close to the gauge and solder the new tube on while the bulb is still subject to extreme cold.

The hardest part is not plugging the tube with solder.

Tom, here's the restoration of a gauge step by step: 1933 Plymouth Temperature Gauge Repair Howard Dennis
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The thermocouple is not reading in my Chrysler.

To clarify, that isn't a theromcouple. A thermocouple is a semiconductor that changes voltage with temperature. This is a mechanical bulb style gauge that uses a working fluid like ammonia or alcohol in a sealed tube. Heat expands the working fluid, moving the gauge. The link above provides excellent information on how this works and possible repair.

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Thanks to all. I looked into the repair. the capillary tube was a .065OD and the smallest ID I found was .08. I cosidered using foil shim. I attempted to find out what fluid was in the new sacrifical unit - no avail.

The folks in the technical departmetn ( of the potential replacement unit) mentioned Williamson Instruments in AR. So - I'm trying that out.

Anxious to see how it turns out. Thanks, Tom

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Joe-padavano, Not to be a nitpicker, but a thermocouple is not a semiconductor. They are made by joining two dissimilar metals together. They produce an EMF, but almost no current with temperature. You might be thinking of a thermistors.

:)

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