1937 water temp gauge, what's the issue???

[John_Mc]

Hi guys the temp gauge on my 1937 Zephyr always reads cold.  When I ground the sending unit the gauge jumps up towards hot in a second or two.  I've been told with the key off, a properly operating gauge should show hot, but when the ignition is turned on, the needle should move instantly towards cold and then gradually move towards the mid range Is this correct?  Thanks in advance.  So do I have. Sending unit or gauge or wiring issue?  Thanks.

Edited September 17, 2016 by John_Mc (see edit history)

[Ken/Alabama]

Bad sending unit. Making the gauge sweep by grounding the wire at the sending unit verified that the gauge is working. 

[19tom40]

John, your description of how the gauge should work is correct for 1939 and up. I don't have a description for the 1936-1938 Lincoln Zephyr gauges, is there one in your owners manual?

 

If your sending unit is bad, you would have to find one for a Lincoln Zephyr as the Ford units work the way you described as proper operation and might damage the gauge.

 

I just did a google on the sending unit and found your question on this from a couple of years ago. You gauge is operating correctly for a 1937 Zephyr. You need the correct sending unit for your car. They are not reproduced, so you will have to find a good used one. Try searching for "parting out 1937 Zephyr" or "1937 Zephyr Parts for sale"

Edited September 17, 2016 by 19tom40
add new information (see edit history)

[John_Mc]

Hi Tom, thanks for the reply, hope see you Sunday in Union.

Yes I questioned the issue with my Temp gauge a couple of years ago and then just forgot about it until recently.  As you know, I like to have every component work as designed in my cats and it's time to get this sorted out.

i spoke to Chris Boos today who was very gracious with his time and he concluded that because my heads are iron, they are not original to the 36-37 models and therefore I needed to replace my sender with a 38 and on and that I would have no further trouble.

intuition tells me however that the sensed is not my problem because I've already replaced the sender with no change.

Now I'm not sure what to do.

[Beltfed]

I have been able to fine replacement senders from Atwater-Kent.  Google it.  Your sender is not a variable resistor type and they will not work in your application, been there done that.  Your sender is a King-Seely type, as is your fuel sender and oil pressure sender.  Your sender is not a passive device like a variable resistor type.  It works somewhat like a turn signal blinker can.

Try doing your grounding and opening of the sender wire at the sender, easier to get to anyway.  This will check your wiring as well as the gauge itself.

Edited September 18, 2016 by Beltfed (see edit history)

[John_Mc]

Thank you for your response, what you say make sense.  I will google Atwater Kent and see what they have.