OK, so i bought a new 150 amp alternator about 8 months ago because me old one stopped working... then 2 months ago the new alternator stops working( wont charge the battery when rpms are below 1500). I bring it back to the shop i bought it from and they repair it for free. NOW about a week ago the alternator has broken again!

My guess is that there is too much power being pulled from the battery and the alternator is being forced to stay on... but I the only mods i have to my electrical system is a 900 watt amp for my stereo. I wouldnt think that 900 watts would ruin an alternator like that but i guess so? Or maybe its not just the amp thats doing the alternator harm.

What should i do?
should i add a 1 farad capacitor to my amp?

Thanks for your help, -Austin

 

to much tension on the belt could kill any pulley. just a thought

 

A capacitor probably wouldn't be a bad idea, but I wouldn't think it would be required. Still, it acts as a buffer between the big current draw spikes from the amp, and the rest of the electrical system. What kind of battery do you have? Is it fairly new? Does it hold a good charge, even if the car hasn't run in a few days?

 

When you go to a high amp alternator you have problems with low speed output. In order to get output higher at idle you need to do one of two things. Turn the alternator faster i.e. smaller diameter pulley, or change the internal rotor stator combination. The problem you are probably having is that the system is discharging ( pulling amps from the battery at idle ), and then full feilding when engine rpm increases enough. This type of cycling puts a lot of stress on the components in the alternator. The cap would help if your base is hitting hard, but if the charging system is not working properly you need to fix this first.