Electrical Issue?
 

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?

RE: Electrical Issue?
 

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.

RE: Electrical Issue?
 

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"