I'm looking for help trying to shed some light on my weird electrical problem.
2003 Volvo S60 2.4T
Returning home, 5 miles to go, I got "El. Power System Service Required" plus battery light.
During these 5 miles got all kind of errors like ABS, ASRS, etc... Lights were noticeably dimmed at the end.
Ordered voltage regulator - Bosch F00M A45 211.
Installed it without removing the alternator.
Recharged the battery as it was drained.
Everything started fine and was running fine for 10-15 minutes. After that I noticed that all lights are flickering. Put voltage meter - voltage was jumping from 14.1V to 16.5V.
I decided to replace original 10 years old battery with new Duracell 750 CCA one.
All was good for first 10 minutes. Then voltage started to jump now from 14.1V to 15.5V.
The VR is brand new, made in Germany.
Could I miss-connect something to have that effect?
Can it be alternator itself?
How can VR produce High voltage?
Appreciate all the ideas.

 

That's why I never recommend replacing just the voltage regulator. You need an alternator, which comes with the voltage regulator.

 

Thanks, but would it be easier just to replace the car which comes with the alternator?
So you think alternator itself can cause overcharging?
How can that be? Any thoughts or theory behind this?
Thanks again.

 

Replacing the regulator is fine if you are doing it yourself. But when someone is paying me for the labor, it is usually more cost effective to do the whole alternator.

Its possible the new regulator is bad, too.

 

Yeah, I'm doing it myself, but does not look fine to me...
Is it not uncommon to get defective part for that regulator?

 

I don't replace the regulator, so I don't know. I've had bad brand new parts though- it happens.

 

Anyone had experience with BOSCH VR been bad out of the box? Does it ever happen? Made in Hungary.

 

Update:
So it was DOA Bosch VR. Returned and replaced - now 14.3V sharp all the time!
Practice makes perfect - the whole procedure took 20 minutes only this time.