Battery voltage gauge drops when I turn on Fog lights

[BullDozer]

So I’ ve noticed for past few months if I manually turn on the fog lights dips a little then comes back up to original position. What’s strange is if I put on high beams no dip. AC same thing. I only notice it when turning on fog lights. Weak alternator? Maybe electrical issue with fog lights? Fog lights work and original bulbs. I can check RPM next time but it feels like a serious draw.

No worries or need to check it out?

[smj999smj]

If the charging system voltage is from 13.2-15.0 volts with the engine running and the fog lamps "on," I wouldn't worry about it.

[twinblown]

Not sure how many amps. fog lights draw but could be normal, these alternators have a feature called "load response control" which help alleviate torque on the engine when certain electrical loads are seen by the alternator therefore applying a smooth volt- amp transition no matter how heavy the load is to the charging system. Like mentioned if your voltage is within specs and your not having crank issues or a dead battery don't worry

[BullDozer]

Okay thanks. Good to know as I definitely could use the exta lighting