Starter shorting/gear shift indicator bad

Hey guys,

I have a 2001 GMC Safari van, same as the Chevy Astro.  A local alarm company installed an Astra 4000RS-2W alarm and remote start system back in October.Yesterday I noticed that my digital gear shift indicator was showing that I was in 3rd gear when I was actually in park, and then it would show something else when I was in drive, and then the red shift indicator completely dissapeared for a while. Then I was on the highway when the starter tried to crank over.  It sounded like a shorted wire, as it cranked over in strange intervals, like a sparking-shorting wire would do.I pulled over and turned it off.  When I turned on the key, it wanted to crank over in the on position.  I pulled the battery cable to reboot the ecm, and all the problems went away except for the funky gear shift indicator problem.  Later on last night, the starter cranking while driving problem started to occur again.  Is this a sticky relay, bad ground, or bad wiring job from the installer?  The garage blames in on the bad ground, and said that his wiring "shouldn't be the problem".  Yea, right.  Today he said he's "too busy to look at it" so I had to drop it at the dealership today for a $150.00 check-out fee.  I think I'll bill him later, if it turns out to be his wiring job. 

I noticed that he used crinp-on connectors for the entire wiring job.  I pulled the 16 pin wiring harness from the Astra 4000, but the problem still ocurrs.

I'm in the Detroit area and the winter weather has just started to get very cold, maybe its a corrosion issue somewhere but I doubt it.

So what do you think?

any alarm, remote start or keyless install should ALWAYS be soldered....the manufactur of the unit that is installed will even tell u that......if u didnt have the problem before the system was installed ....then i would point the finger at the install......i own my own car audio shop and we always do car checkin paper work.....we check out all of the problems that the car has.....if it leaves the shop and has a problem then we cover it....just as the shop u used should too.....the dealership is prolly going to blame the problem on the aftermarket stuff u installed ...even if that is not the problem....i have found that dealerships r not very smart when it come to the aftermarket industry.....if they see anyhting that is not factory, they instantly blame the problem on that.....Where theres is a wire there's a way.