Author Topic: overcharging issues on an aaz (Read 4694 times)

trent77 · « **on:** January 26, 2008, 08:39:00 pm »

I have a 1.9 aaz in a 91 a2 jetta. I replaced the battery after it overcharged. I also added additional grounds from the engine to the chassis thinking that I was loosing ground and the voltage regulator thought it needed juice. Now when the car is running it charges at 13.9 or 14 volts... perfect, then it all of a sudden jumps to 18-19 volts and stays. I am assuming that my voltage regulator is at fault, the alt. is only a few months old though.

My real question is, Are the brushes and voltage regulator one unit? I pulled the brush pack off, but can't remember if the voltage regulator is included in that unit. all help is welcomed. thanks

Vincent Waldon · « **Reply #1 on:** January 26, 2008, 09:22:32 pm »

Yup, that can pretty much only be the regulator, and yup, it and the brushes are one assembly.

Three small phillips screws to remove the black plastic cover on the alternator, and then two screws to remove the regulator/brush assembly.

It's a good idea to remove the ground cable from the battery before you do this of course... otherwise you might let the smoke out of your new regulator !

Vince

trent77 · « **Reply #2 on:** January 27, 2008, 05:25:23 am »

can you pick up the regulators at most parts stores? I just really need my car tomorrow. thanks

Doug · « **Reply #3 on:** January 27, 2008, 05:38:26 am »

It is definitely the regulator. I had similar experience with one on a BMW. Strangely the one on the BMW performed okay until you loaded up the electrical system with lights. Then the voltage would spike up and down as high as 18 volts. You will be able to get one at any good auto electric place where they rebuild alternators. Any parts outlet can get them by order but in Wi. unless there is a cluster of VW's on the road so that your parts place keeps them on the shelf you may have to order it in.. I know that Carquest here keeps inventory based on MTO records so that they have high turnover stock for general repairs available on a walk in basis. That is the way they sell more as well as keep the customer happy.

burn_your_money · « **Reply #4 on:** January 27, 2008, 07:42:02 pm »

I had this problem on my car and simply pulled the blue exciter wire off the alternator. By doing this the voltage regulator in the cluster had to do all the work (I think :? ) It worked fine for the remaining kms I got out of that car. Actually that alt got transplanted into my next car, and the next one.

trent77 · « **Reply #5 on:** January 29, 2008, 05:57:53 am »

so the new part is supposed to be in today. I have been driving my car with the regulator removed. Why is the charge light on the dash not on though? I know it is not receiving voltage, shouldn't it be glowing? thank you

Vincent Waldon · « **Reply #6 on:** January 29, 2008, 09:40:44 am »

Quote from: "trent77"

so the new part is supposed to be in today. I have been driving my car with the regulator removed. Why is the charge light on the dash not on though? I know it is not receiving voltage, shouldn't it be glowing? thank you

The idiot light is an idiot... it doesn't really know about charging current or voltage, only voltage in the exciter loop upstream. You've removed a key part of the exciter loop so there's no initial voltage to trigger the light.

trent77 · « **Reply #7 on:** January 29, 2008, 04:02:18 pm »

sounds good thanks for the help. By the way, nobody seems to like power steering, I think putting a toggle switch on the alternator could be a huge fuel savings. I have been travelling the last 2 days back and forth to school and my fuel mileage seems amazing. I may do the toggle switch this summer! thanks again for all the help.

burn_your_money · « **Reply #8 on:** January 29, 2008, 10:13:45 pm »

you'll want it relayed, that's for sure

jtanguay · « **Reply #9 on:** January 29, 2008, 10:23:15 pm »

ghetto hybrid diesel. no alternator... just batteries :lol:

Author Topic: overcharging issues on an aaz (Read 4694 times)

Doug