Welcome to the Corvette Forums at the Corvette Action Center!

Temperature sending unit 70 vette

red70vette

Well-known member
Joined
Feb 22, 2003
Messages
328
Location
Cortlandt Manor,NY
Corvette
1970 red cpe 350/300
I have been having problems getting a correct temp reading on my 1970 350/300. Gauge worked well until my water pump went and the car overheated. Fortunately no damage to the engine but the temp gauge has not worked accurately since.

Needle on the gauge only moves about 1/2 inch and as a result the reading never exceeds about 120 degrees. I know this is inaccurate and have been looking for a fix. I have read several comments on this forum as well as some others that complain about the lack of correct and accurate temp sending units. Many require changing the wire clip and still don't register correctly.
I don't see that as a worthwhile solution. Why replace one problem with another?

I saw an ad in a magazine for Lectric Limited who now claim to have the correct temp sending units with the button attachment like the originals. I went on their web site and they look pretty good. They big questioon is do the read properly? Has anyone had any experience with these parts or others that work correctly?
 
red70vette said:
I have been having problems getting a correct temp reading on my 1970 350/300. Gauge worked well until my water pump went and the car overheated. Fortunately no damage to the engine but the temp gauge has not worked accurately since.

Needle on the gauge only moves about 1/2 inch and as a result the reading never exceeds about 120 degrees. I know this is inaccurate and have been looking for a fix. I have read several comments on this forum as well as some others that complain about the lack of correct and accurate temp sending units. Many require changing the wire clip and still don't register correctly.
I don't see that as a worthwhile solution. Why replace one problem with another?

I saw an ad in a magazine for Lectric Limited who now claim to have the correct temp sending units with the button attachment like the originals. I went on their web site and they look pretty good. They big questioon is do the read properly? Has anyone had any experience with these parts or others that work correctly?

Hi: I'm just wondering if you changed the thermostat at the same time that you put on the new water pump? ;shrug

Dave: :Steer :pat
 
Yes both the thermostat and the water pump are new. I figure that either the sending unit or the gauge bought the farm when the engine overheated.
 
red70vette said:
Yes both the thermostat and the water pump are new. I figure that either the sending unit or the gauge bought the farm when the engine overheated.

Hi: There could be an outside chance that the thermostat could be defective, even though it's new. I certainally would not rule anything out. I've had new thermostats that were bad to begin with. I always check 'em out first, by emersing them in water at the temp indicated just to make sure that they open up & close correctly. Just a measure that I do to make sure that the thermostat is gonna work after installed. If it's not the thermostat, then more than likely, it's the sender. Really doubt that the guage itself is bad if it worked well before. Good luck.

Dave: :Steer :pat
 
My temperature guage reads first notch in TX. Exept when AC is on or in traffic, then climbs to half guage indication. As you said maybe it is fairly accurate and what you thought was normal wasn't with problems you were having.

Mike
 
The temp gauge in my '69 only reads about 120 max. Never more than a third of the gauge. I think that the sending unit is a thermistor, which can change specs if temp goes too high. I would guess it would have to get quite hot though (like 2X the range, 500 degrees) to cause a permanent change. If I short the wire to ground, I get what I expect, a full temp max reading on the gauge. (zero resistance moves the gauge to hot). This should be a good test for the gauge. With a thermistor, resistance DECREASES with increasing temp and they are good to about 300 degrees.

I placed a digital temp sensor to the upper rad hose and got 190 even though the dash showed 120

If any body knows a good replacement sending unit let me know.

6shark9
 
Lectric claims they are accurate for our gauges.

I have one on order and expect it any day now. I can post how it acts when it is installed if anyone is interested.

Paul
 
I would definitely be interested in the accuracy of the Lectric Limited temp sending unit. Please post or send me an email
 
Post it, I'd be interested, good stuff. Also how to order info, PLZ.

Mike
 
pws69 said:
I will post the results - should be some time this weekend.

Order info: http://www.lectriclimited.com

Installed the sender today and went for a nice warm ride! It works GREAT! With the new GM "replacement" sender, my gauge was reading a steady 240 (just sitting on the left edge of the RED). It was running fine so I knew it wasn't THAT hot.

Now, the gauge comes up slowly as it warms up, then sits steady just below 210 and when I push it (or do other heat provoking things) the needle only goes up 1/8" beyond 210.

Fortunately, I had made an adapter for the gauge wire (didn't want to cut the original connector off) to fit on the "new style" connector on the replacement sender - so I now have the original round connector plugged in correctly. Schweeeet!

LL Part # is 06400759 - $19.00 - you should buy one!

Paul
 
The order has been placed. Thanks for the imput. Can't wiait to be able to see the correct temp on the giage.
 

Corvette Forums

Not a member of the Corvette Action Center?  Join now!  It's free!

Help support the Corvette Action Center!

Supporting Vendors

Dealers:

MacMulkin Chevrolet - The Second Largest Corvette Dealer in the Country!

Advertise with the Corvette Action Center!

Double Your Chances!

Our Partners

Back
Top Bottom