i have an 07 fx4 sohc and the alternator is no good and i live in a small town so i cant get a new one so i went to a junk yard and found a 2002 explorer with a 4.0 sohc and was about to take the alt when i noticed it didnt have the small 1 wire plug on it what does this wire do and can i use the explorer alt on my truck with out the 1 wire hooked up i need help with this asap thanks