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Temperature Guage

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M

mgbcca

Freshman Member
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We're back on the road after laying up the 75 B for winter. Last year, the temperature gauge used to read about in the middle when fully warmed up. Now it reads about 1/4. The engine warms up normally, and there's heat from the heater, so I'm guessing the thermostat isn't stuck open and the heater core isn't full of air.

The temperature sensor in the block has a connector that rotates (rather than a spade-type solid connection). It looks OK, but could that be the problem? Or what else?

Thanks in advance for the help <font color="blue"> </font>
 
Any one know what the hash marks are supposed to represent? I was thinking that an easy way to test might be to place the sensor in boiling water (yes, while still connected) and see if that registers correctly. You could then check either the cooling system or the gauge system.
 
I've never seen a connector that rotates. That sounds finky to me, maybe like it's loose and not a good connection.
 
I've got that RadioShack thermometer... it's very handy, however it needs a special 12v battery (not included).

If you try the boiling water test, remember that the sender suspended in your pot of boiling water will not be grounded (won't work). Be sure to hold the mounting threads with a strong alligator clip/wire hooked back to chassis ground so the gauge will work. It certainly is a cheap test to perform before buying a new sender. I THINK that mid-scale on most Smiths/Jaeger temp gauges should be close to 190 degrees F. Obviously therefore, a sender in boiling water should read a little above mid-scale.

Out of curiosity, how is the fuel gauge behaving? If it is also reading a little low you might want to look at the voltage stabilizer for the instruments. If that is putting out less than 10v the fuel and temp gauges will both read low.
 
The fuel guage seems to read OK. I think I'll pull out the sender and test it. At least it's easy to get at.

Thanks
 
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