Temp gauge wired wrong - help

My temp gauge takes a dive toward hot as soon as I turn the key. I wired it up per this diagram but something's obviously wrong. The bottom connection is +, side/middle is -, top is from sending unit. This is one of the Chinese gauges, which is otherwise fine (fuel & idiot lights okay).

My thoughts: is it wired wrong - maybe mine is installed upside down from the diagram? Maybe the temp sender gone bad or wire grounded somewhere?

I'm thinking this is an easy one, but thought I'd ask before blowing a bunch of fuses in trial-and-error.

There are three connections needed for the temp gauge to work: common ground to the gauge housing, power to the gauge itself and the sender wire from the temp sender unit.

> Disconnect the sender wire at the sender then power up the gauge, the temp needle should stay to the right of cold.

> If so then with the power on, ground the wire you removed from the sender to a good ground on the motor.... does it peg the gauge ?

> Again with the power still on, touch the sender wire to the sender terminal...does the gauge needle peg to hot or stay in the cold ?
....If it pegs to you have a bad sender unit. ~Alan

Or the wrong sender.

Advice like that sure makes it easy. Everything's cool until I connect the sender and then it pegs to hot, so, bad sender.

Now how about "wrong sender?" What temp sender do I need? I see Aircooled.net has a VDO sensor - good?

My temp sender looks a little smaller than the pressure sender, and the temp sender is mounted in the oil releif plug. Aircooled.net says "This is one of our favorite locations!" I didn't put it there so feel free to say that's not a good place to put it. I've only seen the tee setup for pressure/temp under the distributor.

For the most part, oil temp is the same though out the motor with the exception where it exits from the cooler . Do you know where the repro gauges were sourced from so that you can replace the sender with the correct ohm rated one ? ~Alan

These are the Chinese guages that many VS came with... at least that's what I was told.