I'm trying to wire my stereo in the Monte and I have no idea where the 12V constant lead from the harness goes to.

The harness looks like this and the wire is the yellow one you'll see to the right of your screen.

I think it plugs into the fusebox but I don't have any idea where.

So far, no one at Monte Carlo SS.com has replied.

Aftermarket stereo, right?

Your fuseblock should have a few unused hot leads that that connector could plug into, use a test light to see which one(s) are always hot.

The yellow wire does have an inline fuse, right? Because the leads I'm talking about are unfused.

That yellow wire has one prong in the plastic casing and it doesn't seem to fit in any of the slots for the fuses.

For now, I tied the 12V lead into the positive wire leading off of the cigarette lighter and it seems to work ok; I have to turn the stereo on manually each time I turn the key though. The previous owner already had the insulation off of a section of that wire stripped and probably for that exact reason. It'll do until I figure out the cleaner, less "jerry-rigged" approach, i.e. where and how that yellow adapter plugs in and where.

Look for the factory radio's power lead, it may be just the right spot.

Probably stuffed up under the dash somewhere...

Dug around in the dash earlier and still no connector. I guess I'm just stuck with my rigged up stereo with the ability to light cigarettes.

However there is one more issue with the Monte I have to sort out and I'm grinding my teeth over it: it's the A/C system and it makes a high pitched squeeling sound, like you're getting really bad feedback from an old radio. I'm thinking the compressor is shot ...