2001 GA 2.4L idle issues

i had installed a DB electrical HO ALt 200 amp, and im having idle issues im idleing round 500-600 when other places i have read people say there getting 700-850 even so im wondering if it is my car that i need to fix cuz i called DB and they said between 650 to 750rms that alt puts out 105amp and when im at idle i know im not gettin that cuz i notice my light dimming and when i push the gas they get brighter. im only having issues when at idle going down the road im fine even when im blasting my 4K watt stereo. if any one has any ideas please let me know thanks in advance

TEC

compare the size of pulleys both should be the same size.

compare the size of pulleys both should be the same size.

the HO ALT came with a OD pulley so its smaller to make it crank faster

strange, there is small screw that controls throttle plate opening when you release gas pedal see if you can tighten it some.

strange, there is small screw that controls throttle plate opening when you release gas pedal see if you can tighten it some.

is it down by the gas pedal or where?

I'll bet you put the stereo in first, sucked your battery dry by blasting the 4kw, then upgraded the alternator. (my nephew did just that) Get your battery tested (a-zone will do it for free), make sure battery/alt/engine ground terminals are all clean and tight. I think my nephew ended up having to install a super-duper battery just to support the high power audio amp.
Hope this helps.

is it down by the gas pedal or where?

by the throttle plate, try to open throttle plate by hand by turning that part where the spring is, and look under it you will see small screw that stops it when the throttle plate is closed.

I'll bet you put the stereo in first, sucked your battery dry by blasting the 4kw, then upgraded the alternator. (my nephew did just that) Get your battery tested (a-zone will do it for free), make sure battery/alt/engine ground terminals are all clean and tight. I think my nephew ended up having to install a super-duper battery just to support the high power audio amp.
Hope this helps.

Actualy no i didnt i upgraded the ALt 1st i also have 2 batterys i have a stinger SPV70 in the back and stock up front i will have another SPV70 thursday