How to check temp sensor without a guage

[watsongs]

I fired up the engine and ran it around the block today; first time it's been run for more than a couple minutes since the head went back on.  I have the old dash with speedo and gas guage only; the fan never came on th whole time.  Granted, it's 45 degrees outside, but I worried about the sensor being bad - seems like everything else on this car is/was.  The Bentley and Poor Richard books only tell how to check with a temp guage.  Does anyone have an idea of how to check w/out the guage?  Is there a resistance that the sensor should read? If I jumper the wires going to the sensor, the fan comes on (the sensor in the radiator).  

I can get a guage from a local boneyard off a cabby; I'm not sure how to hook it up.  I looked at those little 3-in-one guage packages at the local parts store for $35, but was told I need to get an adapter because of the metric vs english.  Anyone have any experience with these?  Thanks -

Greg

[zyewdall]

I've used the mechanical aftermarket temperature guages (like the 3 in one deal you are talking about).  I just JB welded it to the block instead of trying to find the adaptor to connect it to to a metric hole in the block.  This doesn't really give the same temperature as a water temp gauge, but it gives an idea of what the engine temp is.    If you really can't find an adaptor, I'd imagine you could get an american fitting that fit the sensor, and a metric fitting for the block that was just a little bigger, and solder the two together to make an adaptor.

[watsongs]

I don't mind not having the guage, after all, alot of cars don't.  I'm more interested in checking to see if the original setup is good.

[watsongs]

Got a solution from the local parts store - take a propane torch and gently warm the sensor, see if the fan comes on.