[RASK]

My car was running on the warm side (210) even after I tried most of the tricks read here including the water pump divider plate, which were all great suggestions and none of which should be overlooked. I read a post about inaccurrate aftermarket temp senders from Napa and others. I can't find the post but, a member suggested Lectric Limited. I decided to buy one from LL and test some other sensors I had while using my stock temp gauge from an article I read. I'm not trying to take credit for the article, but here is an overview from the article for your benefit.
I bought a cheap hotplate, put next to car on a stand and then heated a water/antifreeze bath. Made a bracket I could mount the sender in. I used a battery charger style clamp to clamp around the sender and connected that back to chassis Gnd. I extended the signal wire from the car to sender. I used a multimeter with T/C attachment (1% claimed accuracy) and a good thermomenter to measure bath. I took measurements and comparisons at 185 and 215deg. The following results were seen on my stock temp gauge.
The new sender I had in the car (unknown origin) read 15 & 25 deg. too high respectively!
The sender from Napa read 13deg & 13deg to high respectively.
The sender from Lectric Limted was spot on in both cases.
Conclusion: I calculated my car was actually running at 192 when the gauge read 210, big difference. I also have the peace of mind and a temp sender that will ensure my gauge readings are accurate. I can't thank that member enough for recommending a Lectric Limited sender.

Lectric Limited, Inc
708-563-0400

[hillpc]

I wonder if the multimeter with 1% claimed accuracy is 1% of total range, which might be something like 0 - 1800 F. There's 18 degrees right there. Did the multimeter read the same as the thermometer?

[GTOGreg]

I ordered mine the other day from LL, after reading Pete Serio's advice (always worthwhile). I had put on an AC Delco with the round top connetion (not the single spade) - I didn't run the car with it, but I'm sure it would have been out of spec from the word go...score another for these boards!

[RASK]

I know what your saying but, the spec.s from my multimeter stated something like within this range, the accuracy is 1% of reading and within this range, the accuracy is 2%. In my experience, T/Cs are pretty darn accurate. Typically T/C spec.s state a 1-2 deg of accuracy actual reading. RTDs are even more accurate but I have not seen an RTD attachment for a multimeter. Infrared are somwhat less accurate and they typically give an accuracy rating of percentage within a given range.

How do you actually confirm your measuring device is accurate? I know, it's perplexing. In my case, I did not trust my infrared readings. How do I know the coolant flowing past my sender located in the head is at the same temp as the outside surface I was measuring on the head, manifold? What I preferred was to have a measuring device in the same bath as my temp sender so at least I know that the temp should be the same.

What really made me feel most confident is, yes, my T/C reading matched that of my thermometer and with the correct sender, my gage matched my measuring devices.

[webfoot]

Good stuff!

Wonder if I can get a replacement for my autometer temp sender from LL. It has been acting funky.

[diddly]

RASK; Sounds like you've been doing a lot of the same stuff I have recently. I used my camping stove though, so I didn't have to go out and get a hotplate. I also used cooking oil, so that I could heat the stuff as high as I wanted, to see if the variation was linear in the different readings, as temps rose out of sight. My reference instrument is a decent quality digital therm. (The only way to be sure is to have an instrument that is traceable to the national bureau of standards; but a decent quality device should suffice for what we're doing). I got about the same results as you: The 2 gauges I checked (mechanical), were both way off; the best one reading 'only' 25 degrees too high. I've learned that cheap aftermarket gauges are commonly 25 dgrees and more off target. I finally bought a Dakota Digital for my '73 TA (which by the way, sounds like yours: Buc. Red, 4-spd., black int.) But I've always had the intention of also getting the factory gauge back to reading somewhat accurately. I think I'll look into the LL sender. Thanks for posting your results and informing us all!....diddly

[rkolonchuk]

I know this thread is somewhat old but I was wondering the same thing as WEBFOOT regarding using this temperture sender with aftermarket gauges. I have an Autometer temperature gauge that I suspect is reading high. Has anyone used the Lectric Limted tempertaure sender with an aftermarket gauge??

[Skip Fix]

GM also changed the reference resistance around 80-81 for temp senders.A 78 sensor in an 81 car wil show WAY hot!

[Peter Serio]

I've done lots of tests on all kinds of sending units as it relates to the gauges I work on. Bottom line is if you have a car made in the 1960s, a GTO or a Lemans, The sender that works the best is an original GM part that is made out of brass & will read around it's inner edge: star, dot AC-MADE IN U.S.A. - 12 VOLT, dot. If you are missing the original sender, in my opinion the replacement made by Lectric Limited is 99.9 perfect & will read just as good as a vintage GM part. The modern replacement GM sending unit they sell as part number: 12334869, will make your dash gauge read too hot, EVERY TIME.

Don't ask me why an aftermarket maker, (LL) of reproduction parts can get it right when GM can't.

[Cammer-6]

Originally Posted by RASK

I know what your saying but, the spec.s from my multimeter stated something like within this range, the accuracy is 1% of reading and within this range, the accuracy is 2%. In my experience, T/Cs are pretty darn accurate. Typically T/C spec.s state a 1-2 deg of accuracy actual reading. RTDs are even more accurate but I have not seen an RTD attachment for a multimeter. Infrared are somwhat less accurate and they typically give an accuracy rating of percentage within a given range.

How do you actually confirm your measuring device is accurate? I know, it's perplexing. In my case, I did not trust my infrared readings. How do I know the coolant flowing past my sender located in the head is at the same temp as the outside surface I was measuring on the head, manifold? What I preferred was to have a measuring device in the same bath as my temp sender so at least I know that the temp should be the same.

What really made me feel most confident is, yes, my T/C reading matched that of my thermometer and with the correct sender, my gage matched my measuring devices.

Ah i do a quick check on my digital thremometers and IR gun with ice water and boiling water.
those 2 will be within a deg or 2 of freezing and boiling.
be sure and put some salt in the icewater.

[65lemans]

Now will this sending unit from Lectric Limited work for non-Rally
Guage Dashes too ? (The Red Idiot Light). Because the one from Napa reads too Hot all the time. Thanks...

[65lemans]

Anybody ?