I want to test the wiring going to my fuel injectors and dont know which wire in the plugs is positive and which is negitive. I was going to mess around with it till i got a reading, but i dont want it too screw anything up

 

Each injector has two wires in the harness clip. The pink wire is +12V from the fuse block. The other wire is to the PCM, and provides a ground to actuate the injector.

 

Thanks , I checked the positive on them all and they all were very close to 12V ... so now im lost as to why the Noid lite lit up dim, then bright, then didnt lite at all when attached to the #2 ( Only one i checked ) all within 5 seconds of cranking ... Im looking at a fuel injector wiring diagram from shoeboxes site, and it shows a ground coming off of the solenoid valve ... too bad i dont know where the solenoid valve is lol ...