Honda Prelude Forum banner
1 - 8 of 8 Posts

·
Registered
Joined
·
410 Posts
Discussion Starter · #1 ·
alright this ones a little diff then the others, doing a quick search I found nothing. now why would my battery light be on when the car isnt on? its obviously not charging but it shouldnt be on, so its kinda confusing me, just started doing it a couple days ago too along with the blinking oil light but that one is a little more understandable.
 

·
Registered
Joined
·
739 Posts
11_dreams said:
alright this ones a little diff then the others, doing a quick search I found nothing. now why would my battery light be on when the car isnt on? its obviously not charging but it shouldnt be on, so its kinda confusing me, just started doing it a couple days ago too along with the blinking oil light but that one is a little more understandable.
The battery light is actually an alternator light.. It lets you know when your alternator is not charging the battery..

Since your alternator charges the battery to 14.5v, but the battery holds 12v. So with the car off your at 12v, with it on your at 14+

I have no idea what voltage the light comes on in the prelude
 

·
Premium Member
Joined
·
2,144 Posts
it comes on when your NOT charging, Undercharging, or over charging.

Basically, if the Alternator is not putting out any Vlotage/Ampers, or not Enough, or TOO MUCH... the light will turn on.

When the engine is off, there is NO charging going on - hence the light is on. Its normal, totaly not a problem. thats how it is supposed to work.
 

·
Registered
Joined
·
410 Posts
Discussion Starter · #4 · (Edited)
yeah but its never stayed on while the car was off before, I know it works in conjunction with the alternator and lets you know if its undercharging and all that jazz, but why would it just randomly come on and stay on while the car is not turned on out of no where? normally itll just not come on at all unless theres a problem with the alternator or something in the charging system. its just a bother seeing it on all the time while the cars no on ya know
 

·
Premium Member
Joined
·
2,144 Posts
Ok.. so the key isnt being used at all.. and its on?
 

·
Banned
Joined
·
13,157 Posts
thats what it sounds like lol. that the battery light is on even when the key isnt even in the ignition. in which case you have some sort of short or crossed wire somewhere. no clue where to start on that one lol
 

·
Registered
Joined
·
410 Posts
Discussion Starter · #7 ·
im thinking my alternator is getting ready to call her quits soon, wire could be shorting through the rotor and just staying on instead of going to ground. my car also just recently got hella loud, sounds like it could be an exhaust leak, probably is jsut gotta find it, but it also sounds like its coming from the intake so I dont know what to think of it.
 

·
Registered
Joined
·
856 Posts
My experience with this was the brushes in the alternator were shot. I got a replacement set of brushes from a local alternator rebuild place. It was pretty easy to change the brushes. One thing to keep in mind. If your alternator has that many miles on it the slip ring that the brushes ride on can get worn down to the point they will start arcing. That is what eventually happened a couple years after I changed the brushes. When that happened it smoked the brush block and I had smoke coming out from under the hood. Time for a new alternator. I got a couple extra years out of it anyway.:dontgetit:
 
1 - 8 of 8 Posts
Top