Mid year temperture sender question

[Don Shirey]

A supposly NOS sender with "Made in USA" stamped upside down on the neck is for sale on E-Bay. My original sender and other original I know both are stamped with lettering right side up. Were originals stamped both ways??

Thanks in advance,
Don 31553

[Rob A.]

Re: Mid year temperture sender question

I recently sold an original on eBay, (and have seen the one you are referring to). Mine had the markings "right side-up". I have sold over half of dozen originals, none of which were marked "upside-down". They are plentiful, and I would wait and find one marked right side-up.

[Jack H.]

Clear as mud....

The original AC drawing calls for the neck band to be embossed "AC MADE IN USA-12 VOLT". It does NOT define the emboss font, the extra marks which are characteristically present (leading/trailing '*' or dots) nor does it define the orientation of the font (upright vs. inverted w.r.t. the body). If you lay down the JB books for Corvettes that used the AC 153321 temp sender, the definition of 'correct' is all over the map!!!!

Some divisions of Corvette judging insist the band should read '12V' and not '12 Volt'. Some want the emboss to be inverted vs. upright. Some quote the emboss as "AC Made in USA" (note use of upper/lower case!). While, perhaps the wisest JG book ('61-62) simply says judges should observe a 'correct AC sending unit'.

So, the reason you see folks (like me) stating exactly what's embossed on the neck of various eBay temp sender offerings is we get KILLED by bidders sending auction e-mail questions wanting to know EXACTLY what's embossed and whether it will judged without deduction on their Corvette. That's like asking how many angles can dance on the head of a pin (depends on specific year of car, what the JG book says and how much 'slack' the particular judge(s) want to cut vs. the exact text of what's printed).

Personally, I find it REAL tough to swallow that there was a single temp sender emboss machine at GM's AC Division that turned these puppy dogs out in the millions of units/annum and that ANYONE really knows which set of verbage, it's orientation on the part, and specific font (not mentioned/defined in any NCRS JG book) is 'correct' for a given car/year. I believe we DO have individual samples of 'untouched' cars to look at, but anyway you slice it, these are few in number and prone to small samle bias error when it comes to saying what was really right for ALL cars built and shipped in a given time period.

Having rounded up something like 250+ temp senders off GM cars from all time periods, I can tell you:

(1) There's are differences in the font used on the neck band.
(2) Some WERE marked '12V' vs. '12 Volt'.
(3) Some WERE emboss right side up while others were upside down.
(4) The '12V' emboss 'seems' to correlate with early vs. late construction geometry of the part (skinny barrel with indented bottom vs. 'fatter' barrel with flat bottom), but once installed the construction difference can NOT be seen....

In the end, each of us has to decide what's 'right' for our individual restoration/preservation effort. The NCRS JG books are just that--GUIDES, not manuals, blueprints or algorithms on how to restore a particular car. There will be differences of opinion and that's healthy because that's how we evolve and learn!