1999 jeep grand cherokee alarm/rs

yes.  i have had the pleasure of this problem....on some jeeps the data bus will not work.  it will lock up all systems...the locks , windows ,interior lights factory alarm.....etc.  the fix is to remove the positve batt cable and the car is fixed...but you still have a problem  with data bus.   so i hard wire the locks and volia...no more problems.

this has happened to 3 of the about 70 jeeps ive done ..and replacement of the databus unit doesnt fix the problem. you must hard wire the locks.

http://64.85.6.129/extrainfo/diagrams/3430_GRAND-CHEROKEE_JEEP%20GRAND%20CHEROKEE%20LOCKS.pdf

ive run into this problem a few times.... resetting the car will clear up the databus lockup but the trucks will still come back to your store....just like you said....I was using the dlwgmj1 from peripheral when i was seeing this issue..i told the shopmanager i wasnt putting these interfaces in anymore and suggested trying the 457cw from dei and i havent seen this problem since....It seems to be a jeep problem though.  At last years knowledgefest there were many techs that had run into the same problems.....perhaps it has something to do with dealerships reflashing the pcms in these trucks after an oil change or something..