Just as likely a bad connection. Get your battery load tested and you can find or eliminate that possibility. Then you can go from there. I'm betting on a weak connection or a faulty ground, maybe even the solenoid or a relay going south. Electronic suppliers have inexpensive tools for cleaning up male and female plugs if it comes to that. De-ox grease is a must, if you live in a rainy, humid climate, use it on everything electrical you take apart, even you car battery terminals.
