need info regarding my '90 XJ ltd... remote entry?

[dingus]

ok so i was reading through my owner's manual the other day (i've owned my jeep for just a few weeks now) and i noticed it has a section on how to use the power door lock remote... it said that cars equipped with such equipment would have a little black ball mounted up in the overhead console... i went outside with curiosity and found that my jeep does in fact have a little ball to receive signals from the remote and it also has a black box under the rear seat on the driver's side which is most likely the brain for the whole system. i'm wondering if i can just buy a remote for the car and get it programmed. if i can, which years will work with my '90 XJ's existing setup?



tia!

-nate[addsig]

[dingus]

well for those of you who don't know... remotes for this car are $140/ea and all they do is lock/unlock the doors... i'm gonna buy a keyless entry/remote start alarm system from commandoalarms.com for 95 bucks with 2 remotes... definetely not worth going through the dealer on this one...[addsig]

[RookieJeeper]

that black box under your back seat, is your ABS brakes if you have them. [addsig]