Lights Dim

Paulie G · October 28, 2005

Why do my headlights dim when I come to a stop or a near stop? It doesn't seam to bother anything but a little annoying. 2001 2500 HD 8.1L Allison with 105 amp alt.

Is this normal?

Supercop8100 · October 28, 2005

Weak battery. Get a new battery with high CCA.

Paulie G · October 28, 2005

That seems like the obvious but I have I high wattage aftermarket stereo system in it with no capacitor and that will barely make the lights dim cranked up. I can even run it with the truck off for over an hour and no problems at start up.

Your probably right, I just I thought I would see it in these areas.........or wouldn't I

Shaners · October 28, 2005

My old '01 6.0L HD did that from the time it was new... When I sold it it was 4 years old and it still had the original battery.

I don't know why it did that, but it never seemed to hurt anything.

Chronic · October 28, 2005

Do the lights dim without the stereo on at a stop? I know you have aftermarket equipment but I definitely used to notice my lights would dim more at a stop than while driving. That bass really caused the lights to dim while stationary. You might just want to add a cap to see? Couldn't hurt, I'll tell you it definitely solved my problem. No dimming now whatsoever.

Paulie G · October 29, 2005

It's not that kind of dimming. It seems like it's made to do that.

As I slow down to the stop sign, the lights dim with the engine rpm. At a certain rpm the lights will resume their normal shine. While I am at a stop with the truck in gear the lights are fine. Its like the alternator has a slip clutch or something.

Or maybe there is a pause when the lights start to draw power from battery instead of the alternator.

I don't see the charging system gauge move to justify what is happening?

anymore thoughts?

Chronic · October 29, 2005

No more bright ideas from me. Have you spoken with a dealer? Hopefully someone will have an idea!

Shaners · October 29, 2005

Mine would dim as I approached the stop (maybe 20-30 feet?). Once the truck stopped, the lights would brighten back up...

Silverado4x4 · October 30, 2005

Prob. gonna need a bigger altenator with all that stereo equiptment running and the lights on plus the alt trying to keep the battery up is putting a strain on the alt,try putting the truck in netural and bring the rpm up and see if the lights come up to normal, 105 amp alt isnt much for all the stereo equiptment.