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Re: 89 100 alternator or a/c fan problem

DeWitt Harrison wrote:

> >Got a problem with the wife's 89 100 Wagon 116k miles.  When we cruise
> >in the city for 4 day's with the a/c blaring.  It will eventually kill
> >the battery.
> >I've had the battery load tested and it came out ok, batteries about a
> >year old.  The alternator will fully charge the battery if I leave the
> >a/c off for 20 minutes or so of highway driving.
> >I do notice though when the a/c is not running the voltage guage is
> >about 13 + volts.  When the a/c is on and the fan kick's in it
> >immediately drops to 12 volts flat.
> >Is this a problem with the alternator not being powerfull enough to
> >keep up with the draw from the fan or is the fan drawing more current
> >than it is supposed to ?  I seem to remember reading about a similar
> >problem before with the fan on the list.
> >
> >The alternator was replaced last year with a bosch rebuilt 
> >Any Ideas ?

Same_exact_problem here with a rebuilt Bosch 115a alternator, that I've put on the car 
several mos ago.

I was coming back from Montreal 2 weeks ago. Had 4 people in the car, was running 90-100 
all the time, with the A/C and 2x80w H4 low beams on. By midway I've noticed that the 
voltmeter read 12v-i.e. the charging, if existed at all, was very marginal.
None the less, made it to the friends' house, shut the engine off (moron!), unloaded 
friends and their luggage - the car wouldn't start. Waited 10 min - the batt recovered, 
started the car fine. Came home, checked the belt - it's tight.

Yesterday - same thing. A/C does not let the alt charge the batt.

Now a question -- did anyone try to run a smaller dia. pulley on a Bosch alt?
Results? If positive - what was the source of the smaller pulley?

Igor Kessel
'89 200TQ - 18psi (TAP)
'97 A4TQ - on the boat
Philadelphia, PA