car wont start???

[cobraxd12beat]

hey guys ive been having the crapiest luck with my 96 cobra and its getting old anyway i bought this car from a tow yard for $3000 on a lein sale it runs very good and had very clean interior and only 110,000 miles but the paint was very oxidized so i put the car into a paint shop and the frickin guy broke my only key off in the ignition. so i took the lock cylinder out and got the other piece of the key out of the cylinder had a new one cut (just a metal key not a chipped one) and it worked. the car would start as long as the old chipped key was near the steering column but when it started something under the dash was buzzing really loud. so i turned the car off and it still kept buzzing even with no key in and the door shut. so i got under there and traced it to a yellow relay of some sort and unpluged it and the buzzing stopped. i can not find any info on what this is??? so i took the lock cylinder back out and when i did theres a little plastic piece that goes on the cyl that has a lil contacter on it and the lil contacter was broken so when i put it back in the car will start and then die after 3 seconds i really need help on if this relay and the contactor are together or two seperate things?? sorry bout the long post but im tearin my hair out thanks guys

 

[Gallows]

Could be the PATs connection that broken. If so it definitely won't start.