Alternator Question/Problem

[ein bora]

While I had it out I replaced the regulator on my b5 gas to 1.9 idi conversion and now upon start up the alternator doesn't charge and the tach isn't working, once you step on the throttle both work right away and work fine there after. Turn it off - and the no work cycle starts all over again.
Any ideas?

[air-cooled or diesel]

all connections at alt tight? belt tensioned properly? maybe new regulator isn't giving proper signal to wiring (is original wiring for a gas?)? when you put new regulator in did you clean contacts and comutator surface?

[vwsb1974]

had this same problem so when you start it it dose not charge till you give it some gas then its good to go. I replaced my alt and it fixed it

[bajacalal]

I thought this behavior in Bosch alternators of this era was considered normal.

[burn_your_money]

How high do you have to rev it to get things to work? Do both kick in at exactly the same RPM?

[ein bora]

How high do you have to rev it to get things to work? Do both kick in at exactly the same RPM?

About 1500 - 2000 rpm or so and yes both kick in at the same time. I talked to a friend of mine who said it may have to do with the new brushes not seating totally against the matching surface as it's worn by the old brushes similar I guess to what brake pads do to rotors and that the bushes may need some time to wear in and match the surface?

[TylerDurden]

It's totally normal.  Mine all kick in around 1400 rpm.

IIRC, it is due to the LED indicator & diode on the exciter line... they only let a bit of power into the windings, so it takes some rpms to get the alternator to self excite.