My 1997 SC300 lights started randomly blinking on and off even when they are not turned on and the horn blows too. Think it may be tied to a security system issue. Can I disconnect the security system? Any ideas how to fix the problem or what the source may be? Thanks

 

do u have an aftermarket alarm?

 

You've given zero info about the car or it's history. It's not going to go well until you do.

 

Factory security system. over 170,000 miles, purchased with 70,000 miles, recently replaced alternator. Problem started about the same time. Front end replaced before I got it. Alinement shop indicated prior owner lowered front shock towers. Wiper fluid dash light blinks was first sign of problem with lights blinking then horn started later. Still runs good and drives too good not to try to fix the problem. Alarm go off if unlock car with key on drivers door but not on passenger side. Do not have key-less entry key.

 

ALT has a main power plug AND a smaller plug as well. Make sure those are plugged in solid and check your grounds. When the ALT was replaced the engine ground may have been left off or not put back on well.