Depending where the loose connection is i.e. battery cable, stater feed, solenoid, ignition switch etc.
Dirty or loose connections or a bad starter.
check for loose connections
Arcing. The electrical current jumps across the air gap in the loose connection. This creates heat. .
Stop or slow down? It sounds like a loose/worn suspension.
Pulley stop truck from starting
bad battery, and bad alternator not keeping it charged - also bad connections to the battery or loose wire connections on the alternator.
Loose or worn belt?
Yes.
The car will stop if the battery cable comes loose.
You have a loose electrical connection.
Thee fan belt is loose or dried out. Most likely loose.
First clean battery connections, if this does not correct problem the battery needs replacing.