TPIguy87

Alright guys I'm posting this thread because of my own mistakes and can hopefully save someone lots of money when it comes to your alternator.

I thought for sure my alternator was bad because of horrible voltage readings at idle and low rpms, radio would cut off and lights would dim even after installing new alternator. I knew something wasn't right with my system and continued my research which I should have done before hand, stupid me.

The PO had my car built up, and did it well. Not half ***, I mean things are done methodically and very well. BUT. Some things they did I question because this car was a daily driver for them, and I didn't understand the things they did. For example putting an Underdriven pulley on the alternator.

Prior to my latest research I didn't know anything about these overdriven and undriven pulleys, and it has cost me.

So if you or a bud has a car and it doesn't charge worth a s*** At idle first thing I would look at is to see if you have an Underdriven pulley, if you do, change it and see if that helps your cause, if not, seek another thread. I just wanted to share this with anybody who's having a charging issue and cannot seem to pin point why, I'm sure most of you already know a lot of this, but I'm a poor college student and don't appreciate throwing away money I don't need to spend.

Those of you who are wondering what an Underdriven pulley is - it is a larger diameter than stock pulley that causes the alternator to spin slower thus less resistance and more horse power and torque, but it gives less juice to your radio, wipers, AC, etc. at idle speeds and low rpms, correct me if I'm wrong.

Overdriven pulley - a smaller than stock pulley that spins the alternator faster and I'm not exactly sure if it takes away from your horse power and just acts as a stock pulley, sorry for the lack of info.

Thanks guys, hope I helped out somebody today

oscarfromla

iTrader: (9)

Good info, I'm sure it'll help someone out.