Yesterday when i started up my car my speedometer zoomed up to about 40, i revved the engine and it went back to normal. Then today when i was driving home, randomly out of now where my left turn signal was going crazy , it kept flashing on and off but it was struggling. I didnt even turn the left blinker on. The speedo was at zero when i was moving also, but only for about 5 seconds then it functioned normal again. Any ideas to what could be causing this problem? Im thinking it could possibly be the alternator but i would like to hear what you guys have to say. Btw so far that i know of my car is in good running condition except for this weird problem