Re: Charging delays in 4000

[Jon Blake <jonb@u.washington.edu>]

This may or may not prove helpful: my wife's '84 Jetta GLI w/Bosch 
alternator ran much as you describe, though the "trigger" rpm was closer 
to 3,000 than 4,000. About a month ago the alternator failed altogether. 
Closer examination showed worn brushes. $5.00 and some time with the 
solder gun installed new brushes and things have been fine ever since, 
immediate charging upon startup.

Re: noisy bearings. On my '86 csq, the original alternator was very noisy 
in cold weather (c.a. 25F and lower). Original replaced under warranty. 
Now, some years and 100K miles later, the alternator does, on occasion 
makes some growling noises until things warm up. This has gone on for the 
last 2 years or so.

Hope it's just your brushes for a cheap fix.

jonb@u.washington.edu

On Thu, 19 Jan 1995, Robert D. Houk wrote:

> 
>    Amidst the rest of the charging questions, here's another:
>    87 4000S, 4-cyl, at start up, the alternator does not charge at all until 
>    the revs rise to around 4000.  After the alternator "kicks in", it 
>    charges perfectly until the car is shut off again.  Then the cycle 
> 
> Voltage regulator. Sometimes they don't "lock in" ("trigger") until they
> see "ample" voltage/current developed. Generally, with the Bosch alterna-
> tors with built-in voltage regulators, you can replace just the regulator
> assembly (at only half the price of the complete alternator - what a bar-
> gain!). On the other hand, if your bearing are starting to go (or the al-
> ternator is already 7-8 years old, I would make a pre-emptive strike and
> replace the whole thing...
> 
>    during the -30deg. cold spell last winter here in Ohio.   I wouldn't 
>    care, but revving to 4000rpm early in the morning not only bothers the 
>    neighbors, but can't be too good on bearing surfaces when it's a cold 
>    morning.
> 
> Yeah, but if the engine/computer/ignition/et-al is running happily enough
> on just the battery . . . (like I say, *I* would just replace the whole
> thing!)
> 
> 					-RDH
>