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Wrong voltage regulator??

Posted: 13 Mar 2011, 21:56
by Cruz
I recently bought a NOS 068-903-803B voltage regulator on ebay cheap as a spare and I noticed it said 13 0503 14v on it

By chance I was looking through some photos of mine and I noticed one of my current regulator and the writing on that was B0350 12v

This regulator was put on in Belfast by an autoelectricians on a last minute emergency when my alternator stopped charging

Does this mean I have the wrong regulator on my alternator?

Re: Wrong voltage regulator??

Posted: 13 Mar 2011, 22:57
by Cruz
Just done a cross reference using goole and I have found out the regulator on the alternator at present is for a slip ring size of 32 whilst the OEM regulator I have as a spare is for a slip ring size of 28

What does that mean?

Re: Wrong voltage regulator??

Posted: 13 Mar 2011, 23:02
by bigherb
No the charging system is designed to charge at around 14V. Some manufactures put the acctual voltage the regulator is set at, and some just put 12V meaning it is suitable for a 12V system.
As far as the regulator is concered the slip ring size. governs the size of the brush box 28mm slip rings have a longer brush box length than a 32mm.

Re: Wrong voltage regulator??

Posted: 14 Mar 2011, 12:58
by California Dreamin
I suppose in theory: if you fitted the 32mm slip ring regulator to the 28mm slip ring alternator then at some point (when the brushes are fairly worn) the brushes could come out and jam between the bush box and slip ring. Probably not an issue when new as there would be plenty of brush supporting itself in the brush box.
You need to cross reference your alternator number and see which is the correct type.

As far as the regulation goes, most are marked 14 volts and as the other postee said, if it says 12 then that just means for a 12 volt system. If in doubt put a voltmeter on your battery with the engine running, if you are seeing around 14 volts everything is fine.
Bosch specs were 13.9 to 14.2 volts whilst charging.
Martin

Re: Wrong voltage regulator??

Posted: 14 Mar 2011, 13:23
by Cruz
I'm going to change the regulator to the OEM one as that is the correct one for my VAG 65a alternator