battery or alternator?

[S2Knott]

ok, so for the past few weeks this has been happening, i start the car put on the lights and when the rpms come down after start up the lights dim, then if i just step on the gas a little everything brightens up. I charged the battery overnight and that didnt help so i think it could be my alternator.

also i dunno if this is related but when i turn my stereo up with my new speakers the lights flicker, perhaps i just need a capacitor but i dunno it might be related,

 

[loc0gring0]

sounds like a weak battery or the alt.. if your going down a rd and get on it does the battery light come on at high rpm's. also you can pull the neg or poss(not sure what 1)off while its running to test the alt.

 

[mrutkaus]

I am not so sure about taking a battery terminal off while the car is running, I think that can damage the alternator.

I think the fact that speeding up the engine seems to generate some current, that is brighten lights, leads to the idea of a weak battery.

OR, while car is off, remove and clean battery connections?

How old is battery, how well treated?

Mike

 

[hotdimmes]

I think this is a common problem. It happened to me all the time and people always thought I was flashing them. When aircougar did my headers, I had him do the "wiring fix" for dimming headlights and it works perfectly now. I'll see if I can dig up the schematic...it involves some alternator wiring. I believe you cut that thin red wire, then connect the alternator end to the thicker red wire.

 

[Tony2005]

Do the alternator and battery test. It could be that both are shot.

From M&M how to.
http://www.contour.org/ceg-vb/forumdisplay.php?f=56