'61 temperature gauge

[Klas]

Just finishing wife's '61 fleetside short box, 283 cu. in. powerglyde. During a shake down cruise, the original temperature gauge would go almost to the hot side.
Using a digital temperature gun, the thermostat housing read 180 degrees.
Because the speedometer starting going crazy, I decided to replace it and the temp and fuel gauge as long as I had to take the cluster back out.
Sourced and installed Counterpart gauges and speedometer.
Before reinstalling the cluster back in the dash, I tested the lights etc. Letting the truck run outside in 85+ degree heat with the air conditioning on, the needle on the temp gauge would only come up to the cold line.
Checked the temperature again at the thermostat housing, it reads 187 degrees.
I have a new wiring harness, 180 degree thermostat, 01513321 temp sender and no sealant on the sender into the intake.
The gauge is wired correctly (12v to ignition and other side to the sender as marked on the back of the gauge).
Am I missing something or just have a bad (new) temperature gauge?

[Klas]

And I grounded the cluster to the dash for testing.

[Submariner616]

Klas, I am anxiously waiting for a response to your question as I have the exact same situation on my '60 I just finished restoring. I know it doesn't matter, but I even have a 283 and power glide.

[AcampoDave]

A friend of mine uses the stock temp guage and tells me that normal operating temperature is mid way between C and H.

[The Rocknrod]

Read post #3 and #4 here - http://67-72chevytrucks.com/vboard/s...d.php?t=525139

[Klas]

Thanks for the responses so far.
I'm sure I have the correct sender and used no sealant installing it.
Talked with the Truck Shop where I bought the gauge. They suggested checking an adequate ground at the gauge to the cluster, and the cluster to the dash. Also, check that the two posts on the gauge are sufficiently isolated from the housing.
They said they've had good luck with these gauges and want to know what I find. Further offered to replace and test my gauge for proper operation.
Will check today and update.

[Submariner616]

Originally Posted by The Rocknrod

Read post #3 and #4 here - http://67-72chevytrucks.com/vboard/s...d.php?t=525139

Thanks Master Chief. I just ordered the sender from Lectric Limited as mentioned in post #4. We'll see if it works. I should have kept the original sender as it worked fine. I have tried both the original gauge and the stock replacement gauge and they do the same thing. The application list for the sender I have now does list many vehicles. The application list for the one from Lectric Limited is very short.

[Submariner616]

I received the temperature sensor from Lectric and installed it. No luck, the gauge still does not work. The search for a fix continues.

[Klas]

Sorry for the delay in responding. Don't lose faith! I'm running some tests on temperature senders and will report what I've found. To this point I'm finding that not all temperature senders are created equal.

[tchevs]

Not all sensors are created equal. Little variances in materials can make the readings different. The rocknrod gave a link to resistance chart for our senders. if you have a multimeter you can test the resistane that it is putting out. Test it cold. Put your thermometer in the cold water, once you know the temperature of the water, put one lead on the threads the other lead where the wire connects to. It will give you an ohm reading, compare it to that chart. Do the same test with hot water(dont burn yourself), again compare the reading with the chart. If the sensor reads close enough, thats the one you want to use. Plumber by trade, i can tell you that the threads on those sensors are tapered, meaning that as long as the threads are correctly made, you wont need a sealent to make it seal. Tighten hard(better seal, better ground connection), if it leaks tighten some more.

[The Rocknrod]

Thanks, this is all good information. What does it mean by 1/4 way off?

[Klas]

The numbers listed are how far the gauge needle has traveled above the cold (C). So 1/4 is 1/4 way past the cold (C) toward the hot (H).

[AcampoDave]

That's really interesting. It's really something to bear in mind. If you had a Truck Shop or Lectric Limited sender it could be possibe to overheat your motor at 1/2 way off while all the while thinking everything is fine. Conversely, the O'Reilly one would make you believe you're running hot. I'm surprised your thread hasn't received more responses as this is kind of a big deal. Thanks for doing the research.

[Klas]

Tchevs, your information is spot on. And AcampoDave, thank you for your response.
I've restored several vehicles to "as delivered from the factory" for customers.
And those vehicles were expected to drive as they were new.
Unfortunately over the years, original parts are harder to find and we have to use aftermarket parts.
As Tchevs pointed out, not all temp senders are created equal.
Sometimes the conventional wisdom doesn't hold true.
I knew the engine wasn't running hot and needed the cheapo Harbor Freight infared temp gauge to prove it.
This forum is a great resource and we all appreciate the information.