Temperature Sending unit question

[BL in NH]

On a two prong temp sending unit, does it matter what prong the wire to the dash guage attaches too? Long one or short one! Thanks

 

[Old Henry]

Doesn't matter. It's just a switch like a light switch. Current can go either way.

Here's a diagram of the system to better understand how it works:

Close up diagram:

 

[Ralph Moore]

So it looks like one side gives temperature and the other is just an on/off switch?

 

[Kurt in NJ]

Yes, when the 2 wire one reaches the set temperature the gauge will peg hot ---it is one way to know which side has the problem, if the gauge suddenly goes "hot" it is usually the 2 wire side, if it goes hot gradually it is usually the 1 wire side

 

[Bluebell]

Based on the picture, I would hook the gauge to the long one. just in case.

 

[Old Henry]

Based on the picture, I would hook the gauge to the long one. just in case.

Whichever side the wire gets to first coming up from the wire loom on the left side of the engine. So, whichever terminal ends up on the driver's side of the engine when it's screwed into the block tight.