do i need additional parts to hook up an after market door motor to a sp-500 car alarm?

Question

got a 85 toyota pickup with no factory security and no power door locks.

Answer 1

you typically need to setup reverse polarity relays to operate your aftermarket actuators.

http://www.the12volt.com/doorlocks/page3.asp#arp

 
You may want to consult with the manufaturer of your SP-500 though in case parts requried are actually included.