ok this has really been bugging me! my car idles over 900rpm when the headlights are on. it idles normal when they are off! does anyone know why this is happening?!

 

engine speeds up when it senses a high electrical load. maybe your battery is weak.

 

you might want to have your alternator and battery checked....normally if there is a high electrical load the engine will turn more rpm's at idle due to the fact that the alternator needs to turn more revolutions to charge the battery. if there is something wrong with either your alternator or battery you will need to have it checked.

 

thanks guys

 

That's normal. 850 +/- 50 is totally acceptable, especially when the ELD picks up accessory load.

If you think that 900rpm is bad, some ITR's have a tendency to idle 1k rpm or more when the headlights on.

 

the headlights are putting an extra load on the alternator/electrical system so the motor spins a little faster to spin the alternator quicker so it can charge up the electrical system and battery..

 

so ur sayin that its normal for the car to idle like that and nothing is wrong with the car?

 

cool cool, the idle was really bothering me. but not so much any more! thanks guys

 

yeah unless theres been something wrong w/ my car for the past 7 years since it was picked up brand new from the dealer..I also put in an audio system shortly after I brought it home... its been like that and always has been.. in 7 years never had a problem w/ the electrical system and its always done that since new.. so I'd say its normal

 

Here's something to clear things up..

The purpose of the Alternator is to keep the Battery fully charged and run the Accessories while the engine is running.

The reason your engine is idling high is because the more you suck out of the Battery, the more the Alternator has to charge. You suck out 20Amps of Current, the Alternator has to put out 20Amps of Current. It's suppose to be an endless cycle..

But if it's idling higher than it did, say a month before, I would have to say that your Battery's Active Material is getting used up and you'll probably need a Battery sometime in the near future.