96 mark 8 door lock problem

Okay so here is the problem on of my buddies at work was removing an old alarm out of a 96 mark 8 and while in the process the 12v wire from the old alarm sparked on a pink/black wire in the vehicle that was stripped back. After this occure dhe said the door locks in the car on both sides were no longer functional. He checked all fuses and relays and verified they were all good. He then removed the switch and did some testing, with no luck. He then tried applying ground to the switch wires. He said if he applies groud either the lock or unlock switch wires and then presses the lock or unlock whichever wire is grounded the motor will lock the door.  This is supposed to be a neggative door lock system but i did not work on or see the car.  Did he fry a factory alarm would you think, or is he missing a fusable link that is blown?

I told him i would post this up for him on here because there a tons of guys who know more than me, and was hoping one of you could help.

THANKS!!

he states he has checked every fuse with a dmm. I will have my chance to verify his work on thursday when i go back to work, lucky me since im his boss.

Thanks