[TR] 2 versions of TR4 temp sensors

[Carl Sereda]

John,
You may have fixed something that wasn't broke! Here's a long-shot..  there
are 2 different specs for the TR4 Temp Senders.. 1] early TR4 and TR4A have
same specs, 2] mid-range TR4s use a different spec'd temp sensor (which are
now very hard to find). The major vendors all seem to sell just one version
for early TR4 THROUGH TR4A (they don't sell the mid-range TR4 temp sensors). I
have the real deal for my mid-range TR4. Wondering if either your old sensor
eventually went bad, or any of the other things you adjusted caused heating
problem, in mean time you may have bought the only version of temp sender now
available - which may now be misleading your gauge.
The temp sensors can be tested.. put in pot of water and heat water with
thermometer and ohmmeter hooked up to sensor. Then check ohms at certain
temperatures to match specs for early TR4 & TR4A, or mid-range TR4.
If this sounds like fun bI can dig through my files and forward you those
specs.
Or you might just reinstall your old sensor in car and see what happens..
Regards,
Carl
'63 TR4 since '74


Well, after four years of running dead-center in the OK area on the gauge,
suddenly the needle has begun to crawl to the red as I accelerate, then
return to high normal when I come back to idle or 2000 RPM or so. I've done
nothing except fool with the Webers ( an ongoing amusement). The coolant
may have been a bit low, but is now topped off. Checked the timing - may
have been underadvanced at 1000 rpm, now set at 15 degrees at idle. New
sleeved thermostat, even new temp sensor. Heater valve is closed.
What have I done?
Many thanks, as always.

John Howard
65 TR4
73 Stag