Headlight very dim

You're going to want to redo that wiring anyhow. I dont even know if the parking light position has a thermal overload breaker on it (or if that's just on the headlight position).

Be prepared to find a burned red/yellow wire from the hdlt switch to the MF switch. Add a relay to the fog light circuit (and any others you desire). This will unburden the switchgear.

Check the grounds at the front clip. Use your meter to test the voltage reaching the bulbs (leads biased across the low and ground, or high and ground). Then do the same test to check voltage drop with a load.

Good luck.