The Stovebolt Site Forums The Shop Area Engine Shop temperature wire

Where does the wire go from the instrument cluster to the motor. I don't know where to hook the wire to actually sense the temperature of the motor. Please help. Oh btw got the truck running for the first time after 15 years. Sounds like a little tractor.

Are you refering to a 1950 3600 as in your signature line?

If so the temp gauge is mechanical .No wires

yes I am. It appears that there is a solid copper wire that runs from the guages on the dash into the engine bay, but currently it is not attached. Is this what you mean by mechanincal... I know there is no electricity involved. Should this wire be wrapped in insulation?

Or am I totally off. There is a hose that connects just below the carb that runs into the fire wall, could that be for the temp?

Note the motor is a 1958-1960 235

There is a threaded hole on the drivers side of the head about a 1/3 of the way from the back it threads into that hole,it should have a brass adaptor in it.


Pete

that's not a wire, its a tube filled with gas that expands to show temp. it is supposed to connect to the cylinder head.

http://chevy.oldcarmanualproject.com/shop/1955truck2/55ctsm1210.htm

Sounds like the fitting is missing off the end of the temperature line. If so, then his gauge is not going to work.

Is the fitting on top of the head towards the back of the motor. there is a fitting there, that I havn't figured out where it goes...

...pic... 1954 235

As stated above if your tube is cut the gauge is no good. Replacements are available from several vendors

yes - back of the motor toward driver's side

Thanks for the picture. That is the fitting i was talking about. It currently has nothing coming out of it. So I would need to replace it with the connection out of it? Any thoughts on where I can find such a part? LMC

you have to replace the whole assembly i believe. my 56 was the first year that switched to electric, so i'm no help there.

Edit
Removed Information for 1950


...link...

Check the manual for your years 235

Not sure but you may need a bushing

If your engine is a 58 or newer it will not accept a mechanical temp sensor. The thread size for the mechanical and electrical senders are different sizes. I have a 55 engine in my 58 and I had to plumb mine in from the thermostat housing and pluged the hole at the back of the head. If you have the ability you can drill and tap the hole and go back with a new mechanical sender but it won't be easy with the engine installed with the hood on.

no, you have to replace the whole gauge with one that has the threaded end on the capillary tube, as DADs50 linked if your gauge has had that end cut off

Bill

If you have a 56-63 235/261 head, it has a temperature sensor hole in the head that fits the standard 12v electrical temperature sensor.

This adapter will allow those newer heads to be used with the earlier mechanical sender.

Now that I am home I looked at the part. It didnt have a hollow wire out of it. It was a solid wire that ran to the guage. The wire was broke right at the fitting that attaches to the head. If i knew how to post a picture i would.

what type a gauge is in your 50?

It appears to be somewhat original. Its in the 4 window instrument guage 0-212 degrees...

Brad, that "solid wire" is a very fine tube with a hole about the size of a pin, because the end gets "mushed" when the end is broken off you can't see the "hollow", this is a vbery common situation with the mechanical style gauges - a wire would be plastic coated like the rest of the wires in the truck, and you'd only have an electric gauge if someone recently replaced it

edit: that fitting is a temperature sender from the engine which is where a later-than-1950 electrical style gauge would connect
[and here's a working link]

Bill

Brad,

Is that electrical sender the one that you want to use in your engine?

Do you have a gauge that works with an electrical sender?

...your pic ...

That's an electrical sensor
but the gauge you describe is mechanical.
Is there a temp gauge bolted to the bottom of your dash?

I assume the guage works with the electrical sender. Not sure a way to tell.... If i have to replace the whole unit, I don't mind going back to a mechanical one. I think the issue surrounds the guages on at 58-62 are different than for the 50 gauges that I have...

Any advice.

Thanks for everyones help btw!

can you post a pic of your head where the sensor attaches?

you may be able to use a original type mechanical gauge with the adapter Tim linked earlier.

I would get a 220 gauge with your 235

Here is the NAPA part number for the adapter if you choose to use a mechanical sensor.

...pic...

wait for others to confirm if that will work. My 234 is a 54 and the sensor fits without an adapter. I'm not familiar with your year.

Thanks Dad. I will wait to see what the others say.

Brad,

You appear to have an electrical sender attached to an electrical gauge.

Do you have 6v or 12v battery?

If you are asking how/where to connect the broken wire from your gauge, attach it to the post on the top of that sender in your head.

yes, the gauges from 56 up are electrical, if your 1950 truck has the original mechanical gauge, the 'built in' sender end needs to go in the hole where that electrical sender is - what's it look like under the dash? an electrical gauge will have terminals on the back with wires attached, a mechanical gauge will have the capillary tube 'built in', not removeable on that end either

Bill

I have a 12 volt. When you say attache do you mean just wrap it around it. As it appears it was in the past, or is is suppose to go down into the unit. Can i just drill it out and place it down in the sending unit?

red. I will look tomorrow and post a picture. The wife is dragging me to bed.

That sounds like an original gauge for a 216

Can you post a pic of the gauge?

I think the wire had a socket/barrel fitting on the end and it was pressed onto that post in the center top of the sender. You want the single wire to just touch the center post in the top of the sender in the block.

If you have a mechanical temperature gauge, that used a gas/fluid filled sensor tube, a wire will not work.

for the electrical sender the wire [regular plastic coated electrical wire, not bare] would need an end similar to this, the left end in the picture clips on the 'knob' on top of the sender, the 'fingers' crimp onto the wire like any crimp connector - if you drill a hole in the sender you will destroy it

Bill

What you have Brad is a stock "mechanical" gauge which has had the capillary tube cut,
broken, ripped off by someone. This is a thin hollow tube that is when working is a
sealed system from the dash gauge on down to the sensor bulb. That stock sensor bulb,
screws into the seat in the left rear of the head is charged with liquid either under a slight
pressure. When it gets warm it turns to a vapor and puts pressure on the bourdon tube
which expands causing the needle to register the temperature. It's quite common for
the "sealed" line to spring a leak rendering the gauge inoperative. The only fix is to replace the
gauge with it's attached capillary tube and bulb with a new or working used gauge.

The blue "electrical" sender that you have pictured is a much later item and is used only
in conjunction with it's matching "electrical" dash gauge. You obviously bought the truck
with a non working temperature gauge and are confused why they are not compatible.
Once again, one is a broken Mechanical gauge unit and the other is a “12v electrical”
sender only, they don't, won't, can't work together. It’s like trying to marry a horse to a
snake.

Denny Graham
Sandwich, IL