1949 Flathead temperature sensors

Hey guys, I'm looking for a pair of temp sensors for my 49 flattie. Anybody have word on where I can get them? I have scoured parts stores and the internet, and these seem to be as plentiful as unicorn testicles. What gives? I do have a donor pair from an old flattie, but I don't know how well I can trust them in a rebuilt motor.

Also, I want to run two separate temp gauges in my car so I can watch each side of the motor independantly. Is it as easy as running the wiring to each of the gauges independantly? Is there anything I need to be aware or concerned of in doing it this way?

This setup is going into a '49 Merc. I want to get it right the first time. Thanks for all of your help with all the questions I have thrown out there during this build!

 

I bought a set of after market gauges from Napa and the senders that came with it had adaptors in that fitted my flatty.

 

i would run the ones you have and see. don't remember the wiring setup but check on fordbarn for info. the 2 sensors are different and set up to read each bank. i have some laying around if yours don't work. there is really no simple way to test them that i can recall, just hook them up and see.

 

You can test them easily if you have a hot plate and a pan of liquid. Oil is better for testing since it has a high boiling temp but water can be used and it won't catch fire if you get it too hot. If it don't register hot at 212 degrees F then something is wrong anyway. If you had a long test lead it can be connected to the temp wire from the driver side twin terminal sender. Just disconnect the wire from the sender to the gauge and hook your test lead to either sender supended in the water pan and connect a ground led from the sender back to the car. Apply heat to the sender with the ignition switch in the on position and watch the gauge. If you have an infared heat gun you can quickly monitor the temperature of the test liquid in the pan to compare to the gauge in the car.

The twin terminal sender is just a temperature sensitive on/off switch. When it gets to the set temp stamped on the sender, it will open the circuit allowing the gauge to go to H. The passenger sender (single teminal) is an actual temprature sensitive unit that will slowly rise with the temperature applied.

 

I have mine set up like you are wanting to do. It's been a long time since i did it, I hope this helps you. Here are the pics of mine.

 

All good info guys, thanks! hbwoody, thanks for the pics. Looks like the passenger side is home built with the sensor that came with the gauge, and the drivers side is the flathead passenger stock gauge? I have both of the gauges still in the old block, and the drivers' side has two terminals, and the passenger side has one.

My questions now are these:

Can I use the stock sensors I have with a 12 volt system? (I plan to make that change)

If yes, then the drivers' side that has two terminals; can I run just one wire from that (the lower one) to the gauge, and the sole terminal from the passenger side to THAT gauge? Where would the passenger side sensor get the power from to make the gauge work? from the gauge itself?

Thanks for the advice everyone, I'm learning quite a bit here...

 

Like I said its been a long time and I have a short memory but I think one of the sensors needs the other in order to work. The passenger side of mine is what came with the auxiliary Mooneyes gauge.

 

Can I use the stock sensors I have with a 12 volt system? YES

Where would the passenger side sensor get the power from to make the gauge work?
The two sensors had a wire running from one to the other.

 

i have the stock sensors in my 49 and they work fine and are original.if you need new ones then contact shoebox ford or mercuryland for new ones.the sensors will work with 12 volt just put voltage reducers on the gauges.there should be one wire to the pass.side then it goes to the other sensor and from there to the gauge.if you want a modern gauge then you will have to buy sensors that are matched to the gauge you are installing for accurate readings.

 

Here's a print of the original wiring. The 2-pole sender is only a switch that opens when the temperature in the left head reaches about 206 degrees. The single pole unit is actually the temperature sender and was mounted in the right head. I believe Joblot has replacements. If you're going to use two dash gauges you'll need two of the single pole units; the same if you want to install a toggle switch from both units to one dash gauge. NAPA carries a Ford replacement chopper for conversion to 12 volts.

Jim