I have reoccuring issues with my chevy K1500 5.7 liter ext. cab/ service engine light comes on randomly and causes hard shifting and power loss while running also blinkers, and brakelights dont work?

Too many problems in one post, I lost interest. Try spreading them out.

sorry... tell me about it. the issues in my truck are all random and I cant tell what's affecting what. so I figured id put it all out there. my bf sais it all due to my after market stereo, sub and amps wired into something wrong, but I don't see how that effects the shifting or anything else that goes on while driving...

That all depends on who wired it in, and where they wired it in. I can start giving you some answers but not on the stereo wiring. If I did it then I would.

yeah, I had the sound system checked at a automotive shop that installs sound systems early last year, they didn't find anything wired incorrectly. but the engine light comes on when it wants too, either at start or while driving, its soo unpredictable I don't know where to start looking.all of my engine symptoms are at random and only when the light comes on. I can turn my truck off when the engine light is on, and then turn it right back on and the engine light goes off, and it has NO shifting or power loss problems. just doesn't make sence...

Does all this happen when the stereo is blasting? Amps are turned on? I'm thinking a weak alternator.

no, all of this happens when the service engine light comes on. the light can come on while driving, or first starting, or sitting in park. this happens not even every day, I drive every day at least 30 miles. ive been able to drive for days without problems, but when that light comes on, I shift bad driving and sitting still through all its gears, and loose power upon acceleration, and rpms wont go over 2500 on the freeway getting to 60 mph takes forever with the pedal to the floor.

I wonder if the catalytic converter would be starting to get plugged up. May want to have that checked out. The deal on your wipers is that there is a control module in the wiper motor that goes bad and can be replaced cheaper than buying a hole new wiper motor.

My buddy's car was doing the same thing and his code read cylinder b stuck open. It can be dirty, low fluid. Or the cylinder is plugged up.

I will check mine,it has 187000 on it.

Someone more than likely did a cut and splice on the stereo harness connector. All of those wires tie into the ECM on the vehicle and it’s very possible the ECM got fried in the process for you to be having so many random check light and drivability issues. I’d start pulling the codes to see which ones are popping. May require a new computer.