I just put a battery in my 98 blazer 4x4, 4 door, 4.3l vortec. I hadn't run it in about 7 months and it started up right away and all fine. I noticed that I heard what seemed to be the right blinker noise. I couldn't get rid of it. Also, every once in a while it just plain wouldn't start up and I would have to mess with the battery wiring and then it worked. I think that could be do to corrosion or something but the first problem has me stumped. Any ideas?

 

Is the blinker noise coming from the actual blinker? If it is, check the bulb, or even the turn signal fuse.
It could be a bulb. If it is a constant noise, then i'd check the wiring to that blinker.

For the starting, could defintly be loose terminals. Any acid build up could cause a bad connection. If it is an origianl AC Delco batter, they are known to have faulty terminal connections.

 

Put some baking soda on the corrosion and rinse it well with warm water to remove the corrosion. If you have a lot of corrosion you may need to use a wire brush. Clean, tight connections are very important.

Take care of your battery connections first, then see if you still have a "blinker noise"