Ok, I'll try to keep this from becoming a book. The car is a 88 iroc, 350 TPI, auto. It's Dad's car so I don't have all the first hand experience but he's not exactly of the internet generation, so I'll try to relay everything as accurately as possible
Two nights ago the speedo stopped working on his way to work. He started pulling the gauge cluster out in order to see if the speedo cable was turning, turned out to be a bigger job than he wanted to get into at that point. However, after putting everything back together the alarm, which since we got the car has ben dormant decided to spring to life, locked all the doors and won't allow the car to start. Unhooking the battery resets it and allows the car to start, but after a few minutes sitting the doors lock and the ignition is disabled again. The previous owner told us the alarm is a factory installed unit. I guess my basic question is this: we have no need for the alarm, is there a way to go about removing it, or at least complete de-powering it? Also, any insight on the speedo would be good, do the cables commonly fail? Does the gauge? Any info you guys could shed on this would be good.
Thanks
Sean

 

Im not sure about the alarm but my speedo cable on my 88 always failed at the tranny. Check the cable where it plugs into the 700r4, theres a nasty bend that is supported by a metal bracket but over time will still cut and fray. Hope this helps good luck!

 

Thanks for the input. Dad started poking around and found that the wires going to the switch down by your foot (to arm/disarm the alarm I guess) had corroded and broken. Fixing them got the alarm back in order.
After doing some more research it seems that the plastic gear that actually spins the speedo cable breaks easily on 700r4's, I'm gonna look into getting a new one tomorrow, seems like the most logical next step. Thanks again