Testing crankshaft position sensor out of car

WISH30

MEMBER
1999 MERCURY COUGAR
1.8L
4 CYL
2WD
MANUAL
250,000 MILES

Can someone tell me about functionality of crank position sensor? Because I have removed it and as I measure it was fault. But when I bought new one it shows weird measurements. The old sensor measures 1.5k Ohm between positive and ground pin, and when attached to 12v, on the signal pin it shows 1v. I put a hand mixer in front of it to stimulate metal part moving, but the voltage does not change. The new sensor measure 1.5K the same, and when put 12v input, on the signal pin it also show 12v. When testing with the mixer it also not change.

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1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

I just want to confirm you have 3 wires on the crank sensor as you show in that picture. I don't have a manual on the 1.8L as it was not offered in the USA that year so I am not able to provide the diagram and confirm this on my own. This will make a large difference because the 2.0L diagram shows a 2 wire sensor which would be a magnetic sensor. So I just want to be sure you selected the correct engine as well.

However, if you have a 3 wire sensor then it does require 12 volts. However, in order to monitor the signal wire with a volt meter you need to leave it on the vehicle as the air gap is required to be correct and you will not get that using a hand mixer. So you need to back probe the signal wire and the ground wire then hook up your meter. and monitor DC voltage.

The resistance appears to be correct as they are normally between 1.5-2.5 thousand ohms which you are.

https://www.2carpros.com/articles/symptoms-of-a-bad-crankshaft-sensor