1987 P30 engine temperature gauge won't work

[Ryan7361]

OK- I wanted to test my cooling fan(giant one behind the radiator).
So I found my coolant temperature sender-drivers side, high up on the engine block with a single green wire to it. I started the engine, and grounded the sender to the engine block with a short piece of wire- the fan didn't engage, but the dash gauge pinged hard right. The problem-since then my gauge won't work -it's stuck far left! It will still ping-it just won't work normally. What have I done???
Any ideas on how to troubleshoot?

[Lifemember]

The green wire goes to the temp gauge and measures the block temp. You shorted it out and most likely damaged the gauge. This is not how you test the big fan behind the radiator called a fan clutch.

Test fan clutch
http://www.mwrench.com/Whitepapers/FanClutchtest.pdf

[kennyrodgers]

Hi.
Have a look at this thread currently on page 2 of this board. It shows a simple way to test your fan clutch. I would not go sticking a rolled up newspaper in the fan to see if the clutch is OK.
http://www.irv2.com/forums/f22/8-1-v...it-277392.html