[Vwdiesel] voltage regulator issues in 92 Jetta TD

[Doyt W. Echelberger]

I just solved a year-long mystery of why my 89 Jetta D periodically lost 
battery charge and the alternator randomly failed to charge. Like Bryan, I 
suspected the voltage regulator and replaced it.

But the problem was being caused by something else. The complex system of 
belts that turn the alternator, water pump and AC compressor were old and 
slick and hardened, with small cracks between most of the rubber teeth. The 
sides of the belts were shiny and slick and showed the belt fabric. They 
worked sometimes and not at other times. It was a random throw of the dice 
that determined if they were working together at any one time. But I 
couldn't see those tell-tale signs until I took the belts off, because I 
was only looking at them from a position standing in front of the radiator, 
looking down at the alternator.

I could have seen the problem if I had look at them sideways from a 
position inside the passenger front wheel well.

They failed to charge most of the time at high speeds. Long trips at 
turnpike speed were fatal.  But the belts LOOKED OK and had the proper 
tension when the hood was up and I was pushing on the belts to see how far 
they would depress.  They charged fairly well at idle, which threw me off 
because that was when I could put a voltmeter on the system.

Long story short:  New belts solved the charging problem.

It wasn't the alternator.

Doyt
 >>>>>>>>>>>
At 08:24 AM 9/27/2011, you wrote:
>Hi, been having issues on and off for years with this Alt. seems like it 
>is original.
>
>replaced brushes a few times when wires that hold them in on various old 
>ones have broken, I even got new brushes from Rock Auto for like $2 and 
>soldered them in, that works for awhile.
>This last time the light started blinking and it was raining like crazy, I 
>was able to make it home 60 miles on battery and some wipers.
>So, broke down and paid $37 for new Bosch regulator.
>
>Put it in, worked fine for 60 miles to work, then, when I got into parking 
>garage, turn lights off, alt light comes on solid.  Have volt meter with 
>me, sure enough, it is not putting out 13.4 volts as it should.
>Could I have gotten the wrong one and it blew out???
>I am pretty sure I have the 90amp in this car, was W terminal.  I have a 
>wire connected to W terminal but I guess that is factory and goes to 
>harness plug behind the inst. cluster.  I have no tach. in this car, just 
>the clock.
>
>So, does it really matter what voltage reg. you get as a few are 
>listed.  I have swapped it out with others so many times I have no idea 
>what # should be in there?
>I just got this one to replace the failing one that brushes had worn down 
>on.  The must be an issue with the bushing they ride on that is pressed 
>onto the Alt. shaft.
>Bosch 1 197 311 028
>KaehlerPart Number: W0133-1813438
>Notes: (28mm diameter slip ring)
>or
>KaehlerPart Number: W0133-1635481
>Notes: (28mm diameter slip ring)
>
>
>
>If you put them in cocked, you can miss the grounding tab and when you 
>turn the key for pre-ignition you will not get the red pre-test light to 
>go on for the alt.
>That has happened to me.  So, you will have no light at all and it will 
>not charge either.  You can take the volt. reg. out all together and the 
>red light will NOT come on, the housing has to make a ground for the test 
>light to work.
>that is always fun..........
>
>
>I would hate to have to put out $120 on a remanufactured alt. just because 
>of this......errr.
>any idea's
>My local speciallty alt. starter shop closed up about 9 months ago.  Geee, 
>maybe "Autozone" or "Advanced Auto" can help, ha ha ha ha ha ha ha ha ha ha
>
>
>Bryan Belman, Pt. Pleasant, NJ
>04 Jetta Wagon TDI PD, 100hp, 5sp -- running :<)
>92 Jetta 1.6 Eco-Turbo Diesel, 5sp -- running :<)
>82 Diesel Westy 1.9NA -- running :<)
>70 Type 1 stock Elm Green Beetle -- Under Restoration :-)
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