Lights dim at idle

lotas · Post by **lotas** » Wed Apr 12, 2006 2:27 pm

Well I have a 180amp HO Alt from Excessive Amperage, purchased last May. As of...well I'm not sure, but awhile ago I noticed lights dimming and such. Well for the past couple months, 95% of the time when my car is idling, the lights will be dim, and if I rev it up just a tiny bit everything brightens right up. It's only my headlights, and all the instrument lights in the speedometer/clock/dash. No difference in loudness or db level as far as the bass spl or speakers' sound.

I assume my alt is weak or dying? Can you guys verify this? Anything else it could be?

If it is I am gonna be sad, because the alt was expensive and only came with a 6month warranty I believe

Oh, and the weird part is, I just had my car fully serviced, everything tested/replaced and the electrical test came out perfect, "The alternator and battery are in perfect condition". -Repairguy

jron · Post by **jron** » Wed Apr 12, 2006 2:41 pm

are you sure it puts out that much at idle??

ridr4lif · Post by **ridr4lif** » Wed Apr 12, 2006 4:46 pm

Most alt's put out max power around 2000 rpms. So, revving your car up and having everything brighten up sounds normal.

And the tech that tested it prolly tested it at 2k...so i think your fine.

Mithrandir · Post by **Mithrandir** » Wed Apr 12, 2006 4:49 pm

yeah alts dont do their full power at idle, but I think you can get pullys that will increase output at idle

Bwcad1 · Post by **Bwcad1** » Wed Apr 12, 2006 4:55 pm

YOU DO NOT WANT TO PUT AN AFTERMARKET PULLY ON THAT ALT!!!!
trust me it will cause all sorts of issues. i sell excessive and consider nate my friend take it to autozone and have it tested PM me with the results ill talk to nate and get something worked out

lotas · Post by **lotas** » Wed Apr 12, 2006 8:37 pm

Yeah I know they put out less at idle, but its a HO alt...its putting out around 100amps (I believe it was rated) at 800rpm/idle. Thats more than my stock alt put out at 2krpm, and i had no dimming then.

I don't know it just feels weak, maybe I have nothing to worry about?
Thanks for the offer Bill...once I get my car a little more cleaned up I just may do that and I appreciate the offer.

lotas · Post by **lotas** » Mon Apr 17, 2006 1:37 pm

alright something is definetly wrong now.

I start my car up the other night, leaving a buddy's house, and my friend always wants to turn my little Stinger Voltmeter on, so he flips it on, and the car is started and it's reading 11.7v! I'm driving 30mph, up a hill, about 2500rpm and it's reading 11.4v.

As I approached his house (taking him home) all the lights start flickering in the instrument panel (you know how when the key is in the ACC position all the oil/battery/brake etc lights come on, it was flashing those randomly and sporadically). Stopped at the gas station because I was on empty, and it got back up to 12.2v, eventually as I started driving again, back down to 11.8v or so.

Now today (this was like saturday, I didnt drive all sunday) I'm driving to work and it's at 11.5v or so...then it decides to jump up to 12.6v while im driving, eventually 13.8v then jumping back down to 12v or so etc etc

what the hell is going on? Is the alt on its death bed or what?
Man I wish the only two numbers I'd see on that damned thing would be like 14.4v and 12.8v!

I'm gonna take it to Autozone or some place like that and tell them my situation. Do you guys know if this will effect emissions at all? I know nothing about emissions, what is tested or anything, but my tabs and everything were up a couple days ago so I need to go.

Bwcad1 · Post by **Bwcad1** » Mon Apr 17, 2006 1:57 pm

alt is dying take it to autozone to be sure nate will repair it and it will be cheap pm me

Jonathan · Post by **Jonathan** » Mon Apr 17, 2006 2:53 pm

Sound more like a regulator than an alternator, but I'd guess that's a one wire regulator built-in deal so the alt. will have to be changed out regardless.

lotas · Post by **lotas** » Mon Apr 17, 2006 8:25 pm

Oh fun get this. When I posted that last post I was at work. I leave work about an hour or so later. Start the car up, when I start it its at 12.5v or so, does its normal drop to 10.x when I start it and shoots up to 13.8v, great right? Take it to Autozone, have it tested, tests perfectly, nothing wrong, completely normal. Its like I have a ****ing dog that can do some amazing trick and anytime I try to show somebody he just lies on his belly.

Tonight, performed fine, was watching the voltage the whole time, dropped and rose with the RPMs just fine, was around 14.0v when I was driving (although it used to run 14.4v) so I have no idea what the hell is going on. If tomorrow morning it does the 11v thing again I'm gonna assume its the morning cold and throughout the day it sort of "warms" up, I don't know what else it could be.