Unknown Plastic Ticking Noise at Low Idle

Just finished up a timing belt and water pump job which was a whole fiasco that you can view here. TLDR, the timing belt and water pump job went well, but I put the lower radiator hose on backwards which rubbed up against the alternator pulley, which in turn caused a leak. I replaced the hose and flushed the coolant again we're at this problem now.

Noise in my truck at low idle when in the garage that seems to go away when the truck picks up RPMs. Sounds goes in and out. It doesn't sound like it's in the timing belt compartment, but somewhere near the bottom radiator/below the truck. This problem hasn't arose until after the coolant leak and wasn't there after the timing belt replacement. It might just be a piece of stupid plastic in the fan shroud (which I checked and couldn't find) or it could be something else. It sounds like it's more towards the alternator, which would make sense to a degree since it probably got sprayed with coolant the most.

If you also look, you can see the noise goes away after the AC Compressor engages, but I don't think that's the issue, just the problem at low idle:



Just curious what the problem could be. I'm positive it isn't anything serious, but just want to be sure before I drive away into the sunset. Thanks guys!