Temperature Sender

[Tom Hartman]

I have recently put together two cars for friends. One is a '69 SS 396 and the a '69 "Z". Both cars have consoles with gauges. The problem is both cars show they are running hot on the gaugeither car has overheated, just run up in the red on the gauge. I used aftermarket senders that have a blade terminal instead of the factory eyelet. When I changed the wire over, did I screw up the continuity in the wire? Thanks in advance, I am stumped.

Tom

I should have added, both cars are stock builds with new thermostats and clutch fans with shrouds.

[Donnie]

get the sender with the stud and nut.
I had the same problem with the push on blade type.

[budnate]

guy on ebay supposedly sells the right one, claims it will read right, I bought one but have not used it yet.

[njsteve]

This is a similar problem with the Pontiacs: all the aftermarket senders are essentially calibrated for the idiot lights even though they sell them to fit the cars with gauges. So they read waaaaaay high. I am currently hunting for the right sender for my T/A which at the moment reads 210 when it is actually 170 (checked with an actual thermometer).

Read here:

http://forums.performanceyears.com/f...d.php?t=632070

This company supposedly sells a correct sender:

http://www.lectriclimited.com/mainpage.htm

[Tom Hartman]

Sound like I need a couple senders. I will order the ones on-line and let you know how they work. I thought there had to be a connection with both cars having the same problem. Thanks again for the advice and the link.

Tom

[njsteve]

Yes, please update us the minute you get one installed.

I'd love to know that someone is making the right sending unit out there, somewhere!

[Mr70]

Keep in mind too that most temperature senders are positioned in the head,so you're reading an upper head temp. & not a realistic block temp.
Head temps run much higher then the block,and are not always accurate to what is really happening.

[njsteve]

Well, I bought one of the Lectric Limited senders, installed it in the cyl head in the factory spot and it reads 25 degrees higher than the radiator water temperature measured with an accurate thermometer dipped into the coolant.

So much for the accurately calibrated reproductions. [img]<<GRAEMLIN_URL>>/thumbsdown.gif[/img]

The explanation provided above, that the cylinder head will give a higher temp reading than the block location may be true, but that doesn't explain the accuracy of the original factory senders. Were they undercalibrated to compensate for higher cyl head temps?

[Steve Shauger]

Steve try the Wells sender I mentioned. They always read at the quarter graduation. To compare original versus new/repop you would need to verify the resistance levels at specific temps. I have both maybe I'll make a stew and check the resistance levels. If I recall correctly they call out the same sending units regardless of placementfor several years 68-72ish. Possibly the difference was in the gauge ( they may have a different voltage divider in the gauage based on placement and application. I only use the factory gauge as a ball park anyway.

[njsteve]

The Lectric Limited sender reads 63.7 ohms when the car's dash gauge says 220 degrees. (Pos lead on terminal end of sender and neg lead to threaded side of terminal, as well as to actual engine ground)

The thermometer, as well as a capillary bulb mechanical gauge immersed in the radiator at that time, both read 190 degrees.

I'll have to wait til she cools down to get additional readings.