What's the most accurate temerature sender?

[Michael G.]

Have read the posts/archives/...... however am seeking feed back as to most accurate aftermarket temperture sender. Fyi......engine is '66 427/390 hp. The Wells TU5 comes up most often. Opinions/experiences?

[Jack H.]

Re: What's the most accurate temerature sender?

It takes TWO to tango...

There is an inherent degree of 'slop' in the allowable transfer function of the temp sender (more variance allowed at lower temps than at higher temps corresponding to the red line area of the temp gauge). So, even with a factory original part, expect there to be unit-to-unit variance in temp sender response IF you're looking for accuracy at the middle of the dial (around 180-F). That's just the nature of the system...

Then, throw in the service replacement versions of the original temp sender (transfer function was modified over the years to make them "acceptable" in other applications) plus the aftermarket parts (most were designed for GM + Ford + XXX use) and it's quite a jungle out there!

Last, the temp gauge itself was factory calibrated. Early units were attached to an exercise 'box' before the pointer needle was pressed on. Later gauges were assembled with the pointer needle installed, connected to a calibration unit and a precision wire wound resistor was hand selected to make that gauge read properly.

Few question whether their car's temp reporting system is 'off' due to the calibration of the gauge itself, the particular temp sender they've installed, a little of both, or their expectation of the system being dead nuts on in the center of the dial where it was never designed/guaranteed to be highly accurate in the first place!

[Michael G.]

Re: What's the most accurate temerature sender?

Ok.....thanks Jack.

Others with info on aftermarket temp sender giving most accurate reading? Thanks

[Randy S.]

Re: What's the most accurate temerature sender?

Michael,

My plan was to buy a few Wells TU5 and a Standard TS-6 and see which worked best against the temp gun. I think there is a lot of variation in the resistance of a given sender. I ended up using a TS-6 which was close so I never tried the Wells unit

Randy

[Michael G.]

Re: What's the most accurate temerature sender?

Michael,

My plan was to buy a few Wells TU5 and a Standard TS-6 and see which worked best against the temp gun. I think there is a lot of variation in the resistance of a given sender. I ended up using a ST-6 which was close so I never tried the Wells unit

Randy

Thanks Randy. Do I understand you went with a Standard TS-6?.....where purchased? Which engine do you run?

[Randy S.]

Re: What's the most accurate temerature sender?

Michael,

Yes I used the Standard TS-6 on my 66 327/300HP that I found on ebay for $10. The Wells TU-5 units are supposed to be handled by AutoZone but as I said the TS-6 worked fine.

Randy