You check it with the voltage function of the meter with one probe to ground and one to the signal wire. The third wire is 5v reference voltage. On the 90 to 95 4.5 and 4.9L you want -.5v to +.5v with the ISC motor retracted all the way and NOT contacting the throttle lever. If I recall correctly it is the same range on the 4.1L but I would consult a Haynes or a factory manual for that and the wire color identification.
I believe signal wire is blue. The other two are a constant 5V source and a ground. Knowing that, even if the color isn't the same, you should be able to find the signal wire by probing each with your VOM.
The voltage range for the TPS is 0 to 5 volts. I'm pretty sure that the -0.5 to 0.5 spec is for the throttle angle, a parameter interpreted through TPS voltage by the pcm. You can adjust the TPS by throttle angle by using the onboard diagnostics. Otherwise, I'm pretty sure that a 0.0 throttle angle is equal to 0.50 volts signal, which you can find using a VOM to probe the blue wire.
I guess I should have worded my question differently. I know what the wiring colors are supposed to be, I know what the voltage is supposed to be, I know how to correctly set the TPS, I know that you use a Voltmeter, etc.... I was trying to figure out if you can read the resistance with an Ohmeter and if so what range it should be in. I was trying to figure out if I had a bad TPS or a wiring problem without going out and buying a $50.00 part first. Thanks for you input though.
I have not seen anything in the FSM or Haynes manual about this. Being a potentiometer, its resistance will change as it is turned so you could connect a DVM to two of the terminals (signal and gnd I think) then turn it and watch for a steady decrease in resistance. That way you wouls know that it doesnt have any flat spots. The usual way to do that is by simply using the voltage side of your meter instead. All the TPS does is take the 5volts that the ECM supplies it with and cuts it down.
So yes its possible to check its resistance but I dont know what range of values you would be looking for.
Got her fixed, Thanks everyone. Just for reference I did check it with ohmmeter and it had a steady and smooth curve when turned, however the curve was an INCREASE in resistance. With the increase with resistance the voltage was dropping even more. Went and grabbed on from a junkyard for $5.00 and installed to check for wiring problem also, worked like a champ.