Common occurrence. Truck had new battery AND new alternator installed elsewhere for electrical issues but was still having random weird electrical issues and they couldn't figure it out. Found positive cable clamp corroded and causing a significant intermittent voltage drop.

This is the new cable clamp. It must be crimped onto the cable with the proper special tool.

First have to strip off juuuuust enough insulation.

New vs old.

Stripped.

The crimping tool.

Tool.

Cleaning corrosion from all connections.

Replacing main fuse assembly.

Just need to reconnect everything.

Good as new. This actually fixed the random weird electrical issues the customer was experiencing. Unfortunately they paid someone else for a battery and alternator installation to no avail...neither was the actual problem.