1939 LaSalle (Cadillac) Coolant sensor (sending unit)

[Tom Hoczyk , CLC 14044]

Re: 1939 LaSalle 50, probably same part as Cadillac:  Does anyone have a source for an original style coolant sensor that screws into the head on the driver's side of my '39 LaSalle?  Apparently OEM # 1510774.   Also, for the same car, does anyone know the secret of gaining access to the terminals for the headlight FOOT SWITCH beneath the floor?  It seems to be really blocked in.  Thanks in advance!  Tom

[Steve Passmore]

You will have to unbolt the dip switch and let it drop away to get access to the terminals. Two bolts are on the floor under the carpet.

sender unit
https://www.ebay.com/itm/GM-Temperature-Sending-Unit-1939-1952-ORIGINAL-/110469510068

[39LaSalleDriver]

To follow up a bit on what Steve has posted, I am given to understand that NOS temperature sending units are preferable to newly manufactured ones. Reliability issues have been a concern.

As far as the dimmer switch goes, Steve is quite correct that you can do it that way. That is one of the first things I had to do with my car when I bought it and struggled with the same scenario. I found it difficult at best and was even using a pair of very long reach needle nose pliers and a second person above to start screwing it back together while I held it from below.

However, I have since found that it is quite beneficial to remove the access panel underneath the clutch/brake/accelerator pedals. It opens up all kinds of room for working on the dimmer switch and master brake cylinder. It may well save you a good bit of frustration.

[nixiebunny]

Hi. I have a 1940 LaSalle combination car, not anywhere near as pretty as your hearse.

I'm in the process of replacing my temp gauge with one of my own creation, using 12V and Nixie tubes. I have an original 6V temp sender that works - I tested it with boiling water and an ohmmeter. It's much lower resistance than the modern units, 100 ohms cold and ~15 boiling, as I recall. I should be able to part with it.

[Tom Hoczyk , CLC 14044]

Nixiebunny, David Forbes, I'd be very interested in working out the purchase of your old OEM temperature sensor.  hoczyk@yahoo.com   or 260-433-7379   Tom