What does the ICM/BCM control?

The "ICM" on our vehicle's isn't "integrated control module". It means "Ignition Control Module", and it's located inside of the distributor.

We do not have BCM's.

It controls things like the door/key in ignition chimes and interior lights. Had my OE one go bad and had to throw in a used one for too much money, sadly.

If you're having issues with interior lights the IS a fuse under the hood you should check as well. It's a 7.5A one that says "interior lights" but it also affects the ICM/BCM.

My interior lights work and the door/key chime works perfectly. My left turn signal keeps blowing fuse #26. When doing research online I saw a couple different people say it could be that control module. Before buying one I wanted to know what the module controls to see if it really was that module. If it’s not that module then I’m pretty sure there’s a short in my wiring somewhere. Which will be a pain to find.

I've been trying to parse wiring diagrams for a bit now and getting nowhere (lol) but this video shows someone fixing a turn signal issue by replacing the ICU (the shop manual calls it the Integrated Control Unit, that seems to yield better results). The ICU governs hazards and such so it would follow that turn signals would also run through it. Most anything that runs through the interior fuse box is likely managed by the ICU, it seems. Have you tried pulling the bulb and seeing if the fuse blows?