771xvr into 92 325is strange problem?

so yeah, installed the alarm/remote start in this thing the other day.. next day customer comes back in telling me that the car is acting odd. here's his list..

1. tach randomly drops out while driving..

2. speedo randomly drops to 40mph and just sits there no matter how fast he's going..

3. transmission doesn't shift..

tach was found in the white plug behind the cluster, black wire as stated by directechs. tested it and showed every indication of being the tach signal. wire was stripped back and soldered into. (no possibility of poor connection or added impedance) at no point was anything ever unplugged from the cluster while the ignition was on.. unplugged harness, tapped wire, plugged harness back in, started car and read ac voltage..

don't know if perhaps the bimmer doesn't like having things tied to it's tach line?? haven't had the problem before so i don't see how this particular one would be special..

i suppose my next step would be to cut the tach line and program for voltage sense? who knows. the thing that gets me is where do the speedo and shifting issues come from? perhaps the transmission looks for some kind of tach signal?? no idea.. also don't know how he's supposedly driving over 40mph if the thing doesn't shift. he also called today to tell me the car has developed a shake while driving (with all the supposed issues, don't know why the hell he's driving the thing.. besides, he told me he was leaving town on deployment so i had to wait til he got back to look at it)

to me this reaks of a bad tranny.. but i can't say for sure. perhaps this thing has something like the chevy trucks/suvs where if some certain wire isn't connected it goes retarded?? wouldn't know, cuz i hooked up everything directechs listed as being needed, and he's having problems when starting the car by key.. not just r/s.

if someone here could possibly shed some light/ideas i'd greatly appreciate it.. i've got enough grey hairs as is, and i don't need this thing contributing to more of them. haha

thanks guys.. justin

oooh.. good call. might have nailed it with the big ol' knee bolster piece going back in.. was pretty sure i managed to route clear of it, but maybe not? i'll take a peek whenever i manage to get her back in here..

but did this just screw with your tach, or did you have the other issues as well?