Lots of great info in here - Thanks everyone!
I found the article on the ECT and tested mine. 12.something cold, 9.2 Ohms at idle. According to the chart, 9.2 would put the coolant at about 150*F. Is this a bit cool and the sensor needs to be replaced? Or is that right and the hunt goes on? BTW, when I changed plugs&wires about 400 miles ago, both rear (closest to firewall) plugs were just a bit damp.

 

if that was fully warmed up, thats too low. 9.2 ohms is 130-135 degree's, way too low if warmed up. actual coolant temp with a 180 t-stat would be about 195

 

That's what I thought. How much should an ECT cost? Any advice where to get one? Where to avoid?

 

yah, head to your local autozone or whatever and ask for one, make sure you ask for the computer sensor, not the gauge sender
autozone lists one for 17.99 but it doesn't say whether its for computer or gauge

 

btw, glad to see my tech article helped someone and that you could follow it

 

If youre driving the Stang to the parts store, show them the part on the car just to be sure they get it right. Some places arent too bright.

 

AutoZone offered 90 day warranty for $17.99, Advance/Discount 1yr. warr for $23.99, Napa 1 yr. for $32.99!!! Went w/Advance.
Installed it and right after shutting down from a hard drive I got no lower than 8.9 Ohms. Not the drop I was expecting. Any ideas?

 

are you sure you did it right maybe you tried volts. with it running no way you got ohms . ohms is you take the clip off and put the leads onto the two probes and set your meter to ohms. car should be off not at IDLE.

 

u can get ohms at idle just disconnect the clip on the sensor and put ur positive and negitive to the 2 terminals as long as there is no power to the sensor your testing you can check ohms

 

Why are you concentrated on the ECT?.....has the EEC-IV identified a problem with the ECT circuit?....code 51 = open circuit, code 61 = short circuit, and 21 = out of self-test range (.3vdc - 3.7vdc) ...If the ECM hasn't logged a code, why replace a component that is not failing?.... ...FYI...you could monitor output voltage (same way you would do with the TPS)...with the sensor connected....you should have 1.54vdc - .47vdc (158°F - 212°F)....a .8vdc (176°F) engine running is OK.