speedometer quit over 6m ago...now security light on/off,no start at times ????

The speedometer input is not likely to be involved with your current problem. See if your cruise control works if not the vehicle speed sensor (VSS)is probably the problem. Mind you if the VSS fails the ABS light and check engine light should be on, if they are not on the problem may be in the instrument cluster.The alarm issue sounds like an electrical problem but you would need an over view of how the alarm/security system works and then trouble shoot using a wiring diagram to see whee the problem is.Autozone have some popular workshop manuals for free on line once you register (for free) on their website http://bit.ly/autozone_repair_info. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate http://bit.ly/AllData_Repair_Manuals_Online