Alternator not alternating

[vwwestyman]

I asked a couple questions in other threads, but I think I'll make my own thread.

Drove the Van a couple hours away last week. Friday, on coming home, I noticed that the battery light flickered on and off for a little bit. Maybe a minute or two? Then it went out, and for maybe another half-hour it seemed to drive ok.

Then, things started losing power. The ABS light and traction control lights came on, the climatronic started acting wonky, and then the airbag light came on. Then it shut down shortly after.

I was about a half hour from home, so I called the wife, she brought a spare battery with a cigarette lighter plug attached. Let the van charge a bit, jumped it, and plugged in the spare battery. This had worked in a Corrado I had when the serp belt broke.

Unfortunately, that didn't work for more than a few miles, until I ran the jump leads into the window and connected the second battery that way.

Van has been on a charger for a couple days.

Today, I double-checked and the alternator is definitely not charging-no change on the battery tester with the engine running.

Battery light isn't coming on the dash at all.

I DO have 14v (battery charger was attached at the moment) at the blue wire plug on the alt with the key turned on, and do not have voltage when the key is off.

I saw in other threads to be wary of many FLAPS alternators due to them all thinking the Van needs a 90 amp alt when it should be 150.

I also saw that frequently, the problem is just the voltage regulator.

How do I test that?

What to make of the battery light not coming on when I turn the key on, but having 12v at the blue wire? Is the battery bulb a part of the charging system in the same way it is in my old Buses?
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[vwwestyman]

I went ahead and pulled the voltage regulator out. It's brushes look quite short.

But I am wondering about the battery light. Does the fact that it isn't currently turning on, point to something else? I just don't want to buy a new voltage regulator if this points to a different other problem.

Also, what would happen if I put in a voltage regulator that looks to physically fit, but is from a different amperage alternator? I took at peek at the back of the wrecked '05 Passat TDI's alternator and it looks like it's regulator physically fits, but there is no marking of the amperage on the alternator. (I think it had been replaced prior to our purchase.)
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[BatesEV]

If you are curious look up the part number on the regulator. The amps is mainly controlled by the amount of windings the physical alternator has. The regulator limits the amount of voltage that comes out. If the brushes are short then that is your problem. If you want to get creative you could go to a motor shop and buy some brushes for about 5 bucks

If I remember the 90amp and 120amp regulator on a 93 is the same

[vwwestyman]

I went ahead and ordered a VR from the place in San Diego. ( europarts-sd.com ) Chose to do that because they were the only place that listed a correct-looking VR for the Eurovan. There were plenty of places that had them that looked correct, but were listed for other vehicles. I bet they would have worked, but in the end I also decided to support a place that caters to these beasts.

I am still quite curious about whether the charge light requires a working VR, given that I had 14v coming from the wire. Does the circuit go through the bulb like it did with the older cars?
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[Abscate]

It’s hooked into dash module so not easy to troubleshoot like old analog systems. That’s my recollection but I’m having trouble differentiating my wife and her sister which can be problematic
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.ssS!

[vwwestyman]

New voltage regulator arrived today. With the help of my year and half old, I got it installed in a short time.

Battery light comes on with key on, then goes out when the engine starts and the alternator is alternating once again!
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing

[vwwestyman]

I am curious about if there would have been any real difference from a VR like this:

https://www.fcpeuro.com/products/mercedes-voltage-regulator-g55-amg-clk430-mer-0031546506

Part number: F00M 144 146

Compared to the one I bought:

https://europarts-sd.com/voltageregulator2001-2003.asp

Part number: F00M 144 136

Neither match the original number F00M 145 261

Perhaps some small internal difference? Maybe this is why a poster in another thread is having issues with the alternator not charging until the engine is revved?
_________________
Dave Cook

President, Wild Westerner Club

1978 Champagne Edition Westy, repowered to '97 Jetta TDI
1973 Wild Westerner
My Thing