Alternator woes.

[Turd Ferguson]

So few weeks back the alternator died on the VN so I ordered a new Bosch unit (complete with reg)

I did strip down the old one and have a quick clean to no avail, bushes on the reg were very worn.

However installed the new one today, battery light still on, no charge at idle (sits at low 12's when idling, turning on lights etc tanks it)

Voltage readings are the same at B post on back of alternator and the regulator plug so it doesn't seem to be a wiring fault.

Went for a drive and under high revs I saw 13.7V but that was as high as it got, dropping back down to low 12's at idle.

Does it sound like the new alternator / reg is DOA, I swapped the reg for my old one as well and no change...

 

[91SS]

Seems like new regulatory on alternator may be doa

 

[MikeC]

So few weeks back the alternator died on the VN so I ordered a new Bosch unit (complete with reg)

I did strip down the old one and have a quick clean to no avail, bushes on the reg were very worn.

However installed the new one today, battery light still on, no charge at idle (sits at low 12's when idling, turning on lights etc tanks it)

Voltage readings are the same at B post on back of alternator and the regulator plug so it doesn't seem to be a wiring fault.

Went for a drive and under high revs I saw 13.7V but that was as high as it got, dropping back down to low 12's at idle.

Does it sound like the new alternator / reg is DOA, I swapped the reg for my old one as well and no change...

The belt is tight?

 

[Turd Ferguson]

Yes belt is relatively new and is tight.

 

[krusing]

Volts at idle should be 13.4V +/- .3v
and above idle approx. 14.4V
Headlights on, it should drop a little, then come back up to compensate the load/voltage drop.

 

[Turd Ferguson]

Volts at idle should be 13.4V +/- .3v
and above idle approx. 14.4V
Headlights on, it should drop a little, then come back up to compensate the load/voltage drop.

Yeah I'm not even close. Think the new voltage regulator must be stuffed.

 

[krusing]

You can purchase new Brush's for the Regulators,

Are you handy with a Soldering Iron ?
If so, replace the worn out brushes on the old Regulator,
I have done this a few times over the years, and of recent for my VY,
And did the same for my spare Regulator on the shelf.

 

[Turd Ferguson]

Gonna have to wait and see what place I bought the new alternator from says.

 

[VPRob]

I dunno. Maybe clean the major earthing connections? Seems unlikely the new alternator is DOA.

 

[stick3]

the wire from alt to the battery are known to disintegrate when the auto elect replace mine a few years ago and he did check mine and it was ok but he said he seen worse where it just crumbles