Hi all

I realized that my car's interior lights and head lights brighten up when I push the accelerator pedal while the car is stationary and idling? The lights then dim down again when revs drop down to idle.

Is this normal, or should I be looking into this?

Thanks

 

Slight change is normal between running and idle.

A large drop means either the battery is on the way out or the alternator

Normal and quite handy as it helps check your alternator works. If lights go brighter when you raise it above tickover it proves your alternator is pushing out a higher voltage than the battery does. 

But if someone has a car where the lights don’t go brighter it does not necessarily mean that alternator is not working. On some modern cars the alternators have such high output they can give a high output even at tickover speed. 

Ok, hope it is fine as is.

Thank you both

Normal on most cars I've ever had, up until my 2020 focus, goodness knpws why but I bet someone has an answer ..