So the cooling fans in my WRX turn on/off quite often as I'm sure everyones does. When I am idling and they come on everything dims including my cluster and headlights. I have noticed now that even when driving and up around 2500-3000 RPM my headlights still dim when the fans come on..

What can I do to fix this? The only thing I have thought about so far is building a relay system to run power to the headlights directly... or maybe a relay system for the fans so they don't pull power from everything else in the car.

Any ideas would be appreciated

Thanks!

I'd have your alternator checked. Most auto parts stores do it for free. When your alternator is going bad it can cause stuff like this.

How long has it been doing it?

They both already have relay systems. Check for excessive (>0.5v) voltage drop on the grounds.

The charging system isn't working like it should be for some reason. Check to make sure the alternator belt is snug and I suggest you clean the battery connections. It would also be a good idea to have the charging system load tested to see if the battery is still in good shape and the alternator can handle the full output it is designed to produce. There may also be a bad connection between the alternator and the battery or a faulty ground to the battery, as was mentioned already.

Thanks for all the tips guys! Will get the charging system checked as I know the connections are good and I also have a grounding kit installed so those issues should be good.

-It has been going it since I got the car in oct.. we'll see how it turns out.

I've jut started having this exact issue with my 06 WRX. What was the outcome or you? My guess is an alternator issue.

alternator or battery. some batteries just die quickly for some reason and even a good alternator isn't going to push out what isn't there.

In my case I dont think the battery is at fault. Its only 6 months old and is a 880CCA Optima battery.

check the obvious before you dig into alternator or battery problems. Are all the grounds GOOD? all connectors on the battery corrosion free?

check the obvious before you dig into alternator or battery problems. Are all the grounds GOOD? all connectors on the battery corrosion free?

+1 start with the easiest thing first. I learned that one the hard way once :lol: