Battery Light off and on with RPM's?
 

Ive been reading about battery lights and code p1298 on these threads for bout 2 hours and havent come up with an exact solution to my problem so I need a lil' help?

1st things first...2002 Honda Civic LX Coupe...Lowered, Skunk exhaust, Homemade test pipe...all cats and sensors in original positions, aftermarket head unit and subs with amp, LED headlights with aftermarket bulbs, same as tail lights.

2 weeks ago im driving it and the battery light comes on for a while, then shuts off. It does this for about 3 days. Daylight driving, dry outside, only the car running and the radio on. Im driving to work a few days later the battery light pops up and radio, dash lights, headlights, LEDS, and defroster light start flickering off and on and the car dies as Im driving. I parked the car, had it jumped, and parked at a friends...went to autozone, said the battery and alternator was fine! WTF! I put my code reader on and got code P1298 ELD...I replaced the battery and the car ran fine with no battery light for about a week..let me remind you that I havent had any CEL whatsoever! Im driving home last night and the battery light comes on again so I pull over...I turned EVERYTHING electronic in the car on and revved the motor....the light shut off as soon as it hit 3,000 rpm...WTF....the light came on again as the car hit 1,600 rmp and went back down to idle but none of the lights started to flicker....I drove the car home and as long as I had my foot on the gas and above 3,000 rpm the light was off...this morning I started the car and let it idle with nothing electronic on and tested the voltage to the battery...it was at 11v...I revved it up and it went to 13.5v...So I turned everything on and let it idle and the voltage was 10v....then I revved it up and it was 12.5-13v..and the battery light is still on as long as it's idling...as soon as it goes above 3,000rpm it goes off and comes ack on as soon as it drops below...my ecm still has code p1298...any suggestions? Alternator or ELD? I know it's one of the 2 but which one?

Re: Battery Light off and on with RPM's?
 

I say you have a bad alternator, it should be charged up to around 13 or so volts when your car is running and you say your only making 11..this means your ELD should also be good.

Re: Battery Light off and on with RPM's?
 

Thats what I thought it was too! I was throwing a code which threw me off but I didnt have a CEL light...I read a honda TSB and it said that code P1298 is stored in the pcm and thats why its probably there..Thanx

Re: Battery Light off and on with RPM's?
 

First of all, it sounds like you was grounding out at first, i.e. the car flipping out while driving. And then, due to your constant grounding, I think you might have fried your alternator! If I was you, I would be searching for an exposed wire before replacing your alt., so you arent doing it again soon after.