VCCA Home Forums TECHNICAL - 1945 AND NEWER 1958-1960 Temperature Guage problem

Hello to ALL;
I have a question and a problem. (1960 Impala 348)
My water temp. guage showed only a very small amount, and never increased. So, I replaced the sending unit. Now, even when the car is barely warm, the guage reads FULL HOT. Any help? out there?

Impalaroy, it sounds like a ground. When you replaced your sending unit did you hook it up and test it by turning the ignition on and moveing the float up and down very slow to see if your guage was working? Thanks...Oscar

If the wire has a break iit it will read cold all the time. If the wire is shorted it will read hot all the time.
Note theat the needle in a 1960 is counter balanced so when the unit is recieving no power the needle will float to where ever it wants to.

also the threads must make good contact with the intake manifold so no sealers should be used.

The gauge basically is an ohm meter reading resistance to ground through the sending unit, are you getting the hot reading while the engine is cold? or is just reading high when the engine is warm? Was the sending unit you used new? Did it look like the box was opened before? It seems like a defective sending unit
John

I know what it is like to drive a hot running 348! It seems like hours to get them to cool down once they heat up. I would never drive one without a good working temp gauge

Hi; You are thinking this is a gas guage. Thanks

Hi; Thanks; I did use teflon tape on the threads. I will remove it and try again.

Thanks for your reply. The guage reads hi only when the engine is warm. The sending unit was new, purchased from "Late Great". A previous person suggested that the ground was poor because I used teflon tape on the threads. I will first remove the tape and try again, but then will replace the sending unit again with a new one.

Hello again; Well I tried two new senders with the same result, although one of them did not send the guage up over the top, only up to the top. My original sending unit sends the guage up a very small amount from "cold". Not sure where to go from here. If I had a good working temp guage of any variety, I would know what temp the water actually is, and be satisfied knowing what is normal.

Thanks again.

impalaroy,
I know it's been a while since you brought up the temp gauge problem you're having, but I suspect many people are having this issue. I did too, when I got my '60 delivery up and running several years ago. Again two years ago I got a friend's '61 Brookwood running and had this problem of an engine running at 180 degrees and the gauge showing full hot.

I had purchased three different temp gauge sensors from three different souces and they all appeared to have been manufactured in the same factory. Discussion with another old-Chevy guy cleared it up, I believe. Parts suppliers apparently had decided to reduce the number of different parts and combined them into one part number (for the temp sensors). Well, it doesn't work for this vintage of gauges for some reason. I went to an electronic store and got a potentiometer (a variable resister like a volume control), and installed it in line with the temp gauge wire with the engine running at 180 degrees F. I then turned the control to where the gauge showed what seemd reasonable for 180 degrees F. Then I checked the resistance of the potentiometer and then installed a resister of that value in the temp sensor wire. Problem solved. Sseems like it was in the 33-36 ohm area.

Never a problem since.

Jerry