low amps at idle- options?

[Galadrium]

My brother recently bought a '93 notchback 5.0 with underdrive pullies of unknown origin. Since the purchase, he has put on a brand new alternator (stock) and battery. He still has charging issues. At idle (800-900 RPM), the headlights will dim, but by about 1000-1100 the charging guage will go right to the middle and the headlights will be fully bright.

He would like to get rid of them or at least get a decent charge at idle. He was thinking of finding a smaller alternator pulley, but hasn't had any luck locating them, plus the belt might slip off.

Any suggestions? Obviously the cheapest method would be the best method. Get a higher amp alternator? I've heard of people putting on a newer alternator but don't know much about it. Is there any place that sells stock pullies for cheap?

In case it might help someone figure out what pullies they are, the alternator pulley is the exact same size as the stock pulley from my 2001 GT.

Any help/suggestions/stories/information would be appreciated.

Thanks!

 

[makarov]

Tell him to bite the bullet and go for a higher amp alternator. I had problems for years with the stock alternator and u/d pulleys. I finally got smart and went with the powermaster 140amp one wire alt and have had no problems since. There are lots of choices out there, 3g, PA performance, etc. It's not worth the trouble you get with the stock alternator.

 

[gettingfaster]

also change the wire from alt to battery

 

[Michael Yount]

PA-Perf. makes a 95A in the stock size case that doesn't require any modifications to the alternator bracket to mount. Check out their website - www.pa-performance.com -- they have some data on the various size alternators and their outputs at different rpm levels including idle.