Hey guys, I have a 98 blazer 4x4 and have recently had some electrical problems.... My truck started having trouble starting about two weeks ago, I went to autozone and they said I needed a new alternator, got the alternator, replaced it and my car was no different, still needed a jump to get it started. I then replaced my battery and my car ran fine all day, until now. I went to start it, and everything seemed to have power, only it would not start, my power locks also went out and intermittently would switch on their own. I have since pulled the fuse to the locks to avoid that becoming a further problem, all wires leading to my battery, alternator and starter are clean and undamaged.
Any ideas what this could be or how I could diagnose the problem?

 

I suspect that you may have a poor ground connection. On my 98 the ground attached to the frame underneath the metal plate that the battery sits on was bad. I replaced the ground cable and my (similar) problems went away. It's easy to diagnose, but probably just as easy to inspect.

Hans

 

Hans, are you saying that ground is underneath the battery tray , so to get to it , you need to remove the battery and the batt. tray? Or can you access it from under the vehicle?

 

It's been a while, but I believe to get to the ground attached to the front of the frame you have to remove the batter and tray, and then it's in a plastic housing. I'm not sure you could get to this from underneath unless you removed the shroud.

Just pop out the battery.

 

Hans, thanks for the good info. It helps with my projects to have this type of info. I like GM. but why does GM put some of the critical 'grounds' and electrical connections under a battery tray? Then the connections and grounds corrode and there goes the electrical integrity. And why does the battery leak? Because of the side terminal batteries that GM prefers. Tip: don't over tighten the battery terminals.