Climate control sytem problems
 

I have a 2002 Montero limited with a climate control system that for one reason or another goes into fits periodically. on/off/on/off type of thing. I did the wiggle test on all the wiring I could find to no avail. The relay, of course, is going nuts during this fit and I wonder if it is going bad. Do they freak out or just die when they are bad? I am not much of an electrical wiz, I have the 4 volumes of factory manuals but have not had a chance to go through them. I have a circuit tester and multimeter so if someone could explain how I could test the relay, or the control system it would be helpful.