aftermarket cruise control Problem?

[music24]

Hey Cool Cats!I have a problem on S13 Hatch where my speedometer flops completely past 110mph while i drive my car right after warming it up. It works fine after maybe 20-30 minutes of driving. I was told it was a bad speedo sensor so i changed that and i have the same problem. The speedometer does sometimes flip back to 0 if the car rolls back. The car does have an aftermarket cruise control so im wondering if that could be the problem. Maybe wiring or poor components.any input would be great!

[MaximA32]

I have virtually no experience with aftermarket cruise control. I would imagine that there is a signal getting crossed somewhere in there that is causing the problem. I would check the wiring and see if there are any breaks that could explain the problem.