Okay, pardon a dumb question. But what makes it fine all winter long and then act up again in the summer. It has been doing this for a couple of years. Once the solder joints are broken, does it matter how hot or cold it is? Is this an expansion/contraction thing? Are these main relays expensive? Its not really that big of a problem, but I'd put in new relays if thats a sure fix. Thanx