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TR6 Temp Gauge - 74 TR6

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EWD

EWD

Jedi Hopeful
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Afternoon folks -
Finally got on the road after 2 years, minus the windshield. Just couldn’t wait.
Question - After the engine warmed up, the temp gauge never went beyond the first mark. I checked the temp at the thermostat and sending unit with a laser sensor, and it read 155 and 150 respectively. At this temp and having been run 10 miles, wouldn’t the gauge be reading about in the middle? Wire to sending unit ok. Wiring to voltage stabilizer ok ( new stabilizer). Put in a new sending unit and it does the same thing. Fuel gauge works. Anything else to be checked? Wonder if the gauge is faulty. ( Niswonger wants $135 to rebuild).
Thanks for your thoughts as always,
Will
 
First mark being the first indicator past cold. The gauge increases to this point and then stops.
 
Did you also happen to check your ground wire? Sometimes a weak ground can cause a gauge to function incorrectly. other than that, yeah, your gauge might be needing some love.
 
The surface temperature you measure with an infrared thermometer is likely to be considerably lower than what a correct gauge reads. The gauge is reading the coolant temp, well inside the coolant flow. The IR thermometer is reading surface temperature.

Second issue: be sure you have a compatible sensor and gauge. Dunno about TR6s, but often there are several different gauge/sensor combos used as the production run progresses. Sometimes the replacement sensors are different from the originals, too.

Of course, be sure that the thermostat is OK.

You might try removing the gauge and sensor, hooking them up with a battery and some wire, and checking the operation in a bath of hot water. I did this with my TR, just to check the calibration. It's worth doing, in any case.

My guess is that you are OK, and the gauge is sticking.
 
Thanks guys.
If the gauge is sticking, is there a simple repair? I have cleaned it up and replaced the bezel seal; but that’s about it.
will
 
The temp gauge in my ‘73 rarely goes past the first mark.
 
Thx. Will try the temp ground wire. Got a new sensor from Moss and it did the same. Drive about 15 miles yesterday and pushed it a bit. Needle went slightly above first mark. I just need to know when I’m in trouble.
 
FWIW, the normal operating temperature (NOT) of the TR6 engine coolant is around 180*F
If yours is only 150-155 then maybe you shouldn't expect the gauge to read in the middle of it's range.
 
poolboy said:
FWIW, the normal operating temperature (NOT) of the TR6 engine coolant is around 180*F
If yours is only 150-155 then maybe you shouldn't expect the gauge to read in the middle of it's range.
Click to expand...
As I stated above, the gauge on my '73 TR6 always stays at the first mark that's not to say it never goes higher.
On rare occasions when I'm idling in very hot weather I've seen it go above the first mark and approach the middle mark so I know my gauge works. Maybe you don't have a problem.
 
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