Im trying to charge the AC Back up in my 97 F150 and im wondering what color wire i need to apply power to so i can kick the compressor in so it will bring in the R134A, i went to school to be a tech a few years ago and i know that throwing these cheap recharge cans in from walmart isnt the proper way to charge the ac but im not going to go thru the huge hassle in doing it the proper way, the ac hasnt worked in my truck for the past 3 years, the trucks been in my family since 1999, and it worked great then and i think it stopped working right before i got it from my grandpa. Im sure theres a small leak and after 10 years it finnaly just vacated lol. So my question is should i jump power to the compressor or at the low pressure switch to get the compressor to come on so i can charge the system? What wire/wires would i be jumping at the compressor or pressure switch? I know theres a postive and a negative at the compressor connector and its just eaiser to know which one is what before i start applying power to it lol.

I was messing with it yesterday trying to apply power and for some reason the compressor wasnt turning on but i dont know if i was backprobing the connector good enough to make contact with the pin.

Any help would be greatly apperciated. Im sure i could figure it out on my own but it would be much nicer to know right off the bat what wire to apply power to and go from there.

Thanks guys!