Re: [T3] Generator DEAD?

["Jim Adney" <jadney@vwtype3.org>]

On 5 Apr 99, at 23:15, jk wrote:

>     I have 1973 Squareback with dual carbs, and automatic tranny. I
>     replaced
> the generator two years ago. It is Bosch Remanufactured. Till several
> months ago, I encountered a problem, the battery kept draining.
>     A friend of mine told me that I need to replace the regulator and I
>     did.
> The problem still continue. He told me this kind of trick to check if the
> generator is good or bad. He advised me to start the car for a while and
> take out the positive wire from the battery.

You need a better friend. There are 2 things wrong with this advice: 
Never disconnect the battery from a running car that has ANY solid 
state divices in it. This would be fine for a 56 Chevy, but the 
voltage surge that can occur may fry any number of solid state parts 
on your VW. The second bad bit is that you should always disconnect a 
battery's grounded terminal first; this way if the wrench slips, you 
will not draw a 500 Amp2:¯”
 To see whether the car is
> still operating without the battery for a short time that result the
> generator is good. And I did the trick, the car went dead right after
> taking out the positive wire from the battery.

This may mean nothing, but here is how you test your system.

1) Get a voltmeter and measure the voltage across the battery with 
the engine off. It should be between 12 and 13 volts. It it is just a 
little below 12V it is just rather discharged. If it is closer to 10V 
or lower, then it is probably shot, although I would try charging it 
before I replaced it.

2) Leave the voltmeter attached across the battery and start the car. 
The voltage should drop while starting and then come back up. When 
you speed up the engine the voltage should rise until it maxes out a 
14.1-14.4 V. If the voltage rises and peaks at some lower voltage, 
then replace the voltage regulator.

To change the VR, remove the battery ground strap first.

3) If you get different results, write back and tell me what you see.

4) Keep in mind that your charging system may be fine, but there may 
be something draining your battery while you are sleeping. If you 
think this might be the case, remove the battery ground strap when 
you park the car. There should be no spark if you touch it back to 
its terminal. See if things are better than usual the next morning. 
If so, find out what is still on while you are sleeping.

Note that your rebuilt generator should be installed with the little 
punch mark just above the matching punch mark in the retaining strap. 
This aligns the cooling air hole on the bottom so it can be cooled. A 
lot of these get installed randomly and later die from overheating.

Jim
-
*******************************
Jim Adney, jadney@vwtype3.org
Madison, Wisconsin, USA
*******************************

-------------------------------------------------------------------
Unsubscribe? mailto:type3-request@vwtype3.org, Subject: unsubscribe