Hello -

I've noticed a strange thing with my '02 Lancer OZ Rally - when driving at night (or whenever it's dark enough to see the headlights) and I use the power windows, my headlights fade quite noticeably. The only time this isn't noticeable is when I'm on the interstate, travelling at a decent speed. This phenomena can really be seen if I'm sitting idle with my headlights on.

Does this happen to you guys or do I have a problem with my electrical system? It seems like the power required to roll the windows up wouldn't be that huge of a drain on the electrical system, but for my car it's an obvious issue.

I'd really appreciate your input. Thanks

 

when it rains, your car is requiring a lot of current for your lights, wipers, a/c defrosters and all your power equipments. normally this shouldn't happen, but if your belts are loose or wet allowing some slippage, this is what is happening. hence it shouldn't cause some alarm.

 

Also check that the battery connections are secure.

However, keep in mind that at idle the alternator is spinning much more slowly than when you're cruising on the freeway. Therefore, it's more of a strain for it to produce the rated output.

You'll really notice that your headlights will dim when any kind of an electrical motor starts up (e.g. interior blower fan, radiator fans, power window motors, wipers), because electrical motors have a higher current requirement for startup vs continually running.

As on many Japanese cars, there's not a lot of excess electrical capacity, so unless a higher amperage alternator is installed, this is just one of those things we have to deal with.