One v. Two Wire Temp Sender

[ghostrider2]

Hello! On my 81 van with a recently swapped in 1.6TD JX motor, the temp gauge isn't working in the old (pre-84) console. I've checked all the electronics and they are working. The sensor is getting around 10 volts and the gauge moves when I short the plug.

After a bit of research it seems there are JX motors with a temperature sending sensor with one wire but mine has a plug with two wires. Is my old console expecting the one wire version? Is there a way to get my two wire sensor to work? It looks like a pain to swap out the whole flange where the sensor is.

Thanks!

[ORCoaster]

Would one of the wires work to the gauge if you just grounded the other?  Most of the time there are two wires but one is ground.  So try that and let me know if it works.  Brown is normally the VW ground color.  Try that first.

[ghostrider2]

Yes, one wire is ground, and goes to ground as well. But it still isn't working. I'm wondering if the resistance for the two wire sensor is different than the one wire sensor hence the gauge is not getting the right information. I couldn't find concise enough information online on why there are different sensors and which sensor is which.

I suppose the sender itself could be bad but I'm not sure how to test that when it's installed.

[ORCoaster]

It is the temp gauge right?  Then you put both leads on a resistance meter and measure the resistance cold.  Then warm it up and it should change one way or another.  Not sure if it would increase or decrease.  But at least you would know what it was in both cases.  Does it meet the specs of the single-wire gauge?  I would be looking it up on parts sites and see if they can give you a range for it. 

These electrical problems are the worst to solve but yield the biggest smile when you finally do figure it out.

[fatmobile]

I don't know much about the '81 van cluster.

 If it is the same type of gauge as the MK1 or 2 there is a T-shaped connector on top of the sensor.
And 10M1 threads
 
 I don't have much experience with the various 2-wire sensors but if you ground the wire to the gauge and it pegs,
 then doesn't work when connected to the sensor.
it's probably not the gauge.
 
 Can you measure the resistance of the sensor?
See what range it runs in.