Serious Charging System Problem

Jobe Tichy bimmer_dude at
Sun Apr 20 03:36:47 EDT 2003

[ Converted text/html to text/plain ]

Hello Listers:

Well, in response to what was merely irritation, I now have a totally
dysfunctional charging system.  A few weeks ago, I noticed that at idle, the
lighting on the car would flicker and this would go away upon throttle.  In
response to this, several of you suggested checking the contacts on the back
of the alternator and the field wire.

Today, I was going to inspect the wires and clean them.  I proceeded to remove
the field wire and the main contact from the starter.  Each were very rusty
and corroded.  I cleaned with electrical cleaner and added dielectric grease.
I acually cut and added a new field wire connector.  I buttoned up the job,
which proceeded very nicely, started the car AND ONLY 11.7 VOLTS WERE
ATTAINABLE.  I thought maybe I may have had something loose so I redid all
connections and circumvented the field wire harness in case this was bad.
Again, only 11.7 volts attainable.  I  was unable to remove the brushes due to
its positioning without removing the alternator (which I did not have the time
and tools to do).

Needless to say I tried to trouble shoot this before driving home so I could
avoid dying on the freeway in case the charging system didn't work and the
battery would totally drain itself out.  Well, I got the gumption to just do
it and the system held 11.7 volts the entire way home so this leads me to
beleive the charging system is charging, but at very insufficient levels.  My
thoughts are compounded by the fact that I turned on every accessory and
dropped the volts to below 10 because all of the battery idiot lights went
off---but I turned all of the accessories back off again and the idiot lights
went out; thus, there must be some charging going on but not beyond 11.7

So, this sounds like voltage regulator/brush assembly has totally crapped out.
Do you all think this is the case?  Again, I didn't have the opportunity to
pull the brushes out, but then again I didn't touch it when in there.  Any one
have any thoughts on this or experience this.  I seriously doubt its the
battery because I've had no issues previously with it and I had only worked on
the alternator connections today.  Could I have possibly broken something else
on the alternator?  My understanding of the alternator that it's VERY UNLIKELY
anything will break except for voltage regulator/brush assemblies and bearings
and other than that, altnerators have no other problems.

I have a feeling that a voltage regulator/brush assembly in going in no matter
what.  I just want to make sure that I didn't break anything else....

Thanks for all your time and input.


Add photos to your e-mail with MSN 8.[1] Get 2 months FREE*.


More information about the 200q20v mailing list