Temp sender issue

['79squared]

So I have tried two temp senders http://www.oreillyauto.com/site/c/de...?keyword=wt359 and http://www.summitracing.com/parts/smp-ts76 and both are reading my temp at about 260 (pegged) when warmed up. I know my motor is not running this hot nor over heating. I dont want the sender to be in the intake (1/2"npt) so I am running the (3/8"npt) in the head. Aluminum heads with headers. Does anyone know which sender will not read so high? Or is there a way to maybe put in a resistor or something? I think the gauge is out of an '86 but I'm not 100% sure. The gauge is the one with the temp picture, not the word. If that makes any difference. Thanks and if I've left out something let me know.

[rich weyand]

See this: http://67-72chevytrucks.com/vboard/s...31&postcount=5

You need a GM #8993146 or equivalent. That Summit TS76 part cross-references, but aftermarket and auto parts stores senders are sort of generic, and not a good match for the gauge. Engine doesn't matter, just the gauge, because the gauge and the sender have to agree on how much resistance equals how many degrees. You are best off with an NOS part.

Just poking around on Google (GM #8993146), I find some possibilities.
http://www.ebay.com/itm/NEW-GM-TEMPE...-/400339842388
http://jnjvette.com/store/index.php?...product_id=632
http://www.oldsobsolete.com/products...h-nos-8993146/

['79squared]

I'll have to give that a shot thanks. Off to order number 3 haha.

[greg64]

If you disconnect the sensor wire, with the ignition key on (gauge has power), what does the gauge show? It should read cold. If it sticks at 260, I think the sensor wire is grounding out somewhere.

[rich weyand]

BTW, if the gauge was replaced at some point with a reproduction gauge, then all bets are off. In that case, you might have to experiment with different senders to find the right one. But for the factory-installed gauge in years 1979 and later, that's the sender.

['79squared]

We've tested the gauge. It works. Plus I can watch it go from 0 to 260 on warm up and then when I drive it I can see the temp fluctuate when the water is cycling. I know it works. The gauge was taken from a 86 donor dash. I just ordered #8993146 so I will know soon if I have hit the mark or I own 3 that all read to high lmao!

[mattcrp1]

I am dealing with a temp sender retro fit issue my self. I have found the dash gauge makes a difference. There are about 3-4 different senders.

[hatzie]

Originally Posted by mattcrp1

I am dealing with a temp sender retro fit issue my self. I have found the dash gauge makes a difference. There are about 3-4 different senders.

Correct
The part # referenced above is correct for @ 1983 - 1991 CK & RV squares and some of the 88-91 T400 CK chassis trucks. GM probably used it on at least the B body cars too...

Prior to 1983 it gets dicy finding the correct sender. There were several different senders in 3/8" and 1/2" and several different connectors for them.
The Nail Head 1/2" dia transducer sender that GM used on everything from the C3 Vettes to the CK trucks is discontinued and nothing in the aftermarket or from GM properly matches the Temp to OHMS profile of the original transducer. There are a few that are close

This is a pretty good GM temp gauge troubleshooting guide from Wilcox Corvette.

Corvette GM temp gauge troubleshooting