Ed Fisher

You are obviously not afraid to dive in there so may I suggest an automotive stethoscope? With the longer probes you can pinpoint exactly what you are listening to real-time. For instance, listen to the alternator, the A/C compressor, the idler, and every whirring thing under the hood. Then enable your AC or heater and listen again. The change in pitch will be immediately noticeable with the stethoscope. They are less than 10 dollars or so at a good auto parts store. You can use it later to impress your friends. I'm still concerned that the 'electrical burning' smell you noted has not been found. That is a smell far different than a belt slip would cause. Your alternator may indeed be on its way out and the problem, at least right now, is intermittent. Don't know obviously, so this is just a speculation, but years of troubleshooting have taught me to keep digging until I find a root cause.

Funny story about the stethoscopes. I have a 'used car bag' that I carry in my trunk in case I stumble over a for sale car on the side of the road that interests me, or a friend wants me to look at a car for them, or I myself am looking. I ask the owner all sorts of questions before bringing out my bag of goodies. I have a seriously big flashlight, clean inspection gloves, a spot rot magnet gauge, and finally my stethoscope. The owners watch me slowly pulling out all of this stuff and just before I begin the inspection and just after I hang the stethoscope around my neck I say, "Is there anything else you'd like to tell me about the car before I begin?" Man, it is like they are going to confession and they start barfing up all kinds of things from a small fender bender in a parking lot to who-knows-what-else. It is hilarious and also quite effective in learning a car's history.

Ed
Dallas, Tx