Alternator issues?

[dr_mat 0]

This is a new one on me.. anyone seen the following?

 

The alternator warning lamp on the dash isn't lighting up any more on the VR6, even before the car is started. Odd thing #1. Initially I assumed that was because the bulb was gone ..

 

Just now I took a voltmeter to the battery, started the car .. NO charge coming from the alternator (battery reads only 12.10 volts - the engine is running 100% on the battery) .. then I chuck the headlights on and check again .. the alternator starts charging .. 14.3 volts showing at the battery.. lights back off.. still showing full output voltage.. huh?

 

Anyone got any ideas which component to blame first? :)

 

Seems to me it's more likely to be the alternator's regulator circuit. As far as I know it's original, 140k miles.

 

Thoughts?

[Kevin Bacon 5]

Yeah seems like it needs some electrical load to kick start it's charging circuits, what ever they be. As we know, it should start charging the battery immediately. I don't know squat about alternators.

 

Perhaps a good time to source a good used replacement, just in case?

 

Having alt issues myself at the moment, I enquired at VW as to prices and they're pretty scary. Around £200+VAT exchange for the 70A and £300 odd for the 120A.

[Supercharged 2]

Yeah sounds similar to issues when using an aftermarket regulator which is 14V rather than 14.4 - you have to blip the throttle after startup to get the light to go out...

 

Maybe worth trying a different pack but at that mileage I'd try and find a genuine replacement alt - maybe look on eBay?

[volksworld13 0]

i had some old invoices ,with my old kr alternator playing up, a local alt and starter specialist , rebuilt it for not that much money, replaced diodes,bearing, brushes. thats all that go wrong really. try and find a place that will recondition your old unit, you maybe suprised how cheap it may be.

[Kevin Bacon 5]

Yeah sounds similar to issues when using an aftermarket regulator which is 14V rather than 14.4 - you have to blip the throttle after startup to get the light to go out...

 

Maybe worth trying a different pack but at that mileage I'd try and find a genuine replacement alt - maybe look on eBay?

 

None of the VR6 alts are 14.4V mate, they all say 14V on the plastic casing.

 

Well, in reality they deliver 14V from cold to replenish the battery, then trickle at 13.8V for the rest of the journey.

[dr_mat 0]

Yeah, that's just it, the light is never on, no amount of blipping the throttle or dropping the revs will cause it to come on. I suspect I need a new regulator circuit.

The prices are a bit eye-watering, particularly as the heavy engineering bit (the coils, brushes, and magnets) are presumably ok because it will charge at times. ECP have a Lucas alternator that works out at about £150 exchange (currently not in stock of course). I might try calling a dealer and see if they sell the regulator separately.

[volksworld13 0]

try gsf, they gave me a good price on my 2.0 8v alternator.

[dr_mat 0]

GSF don't have an alt for the VR6 listed.. :-\

I did fid a place in london ones who seem to be quite helpful. Should be able to get a refurbed genuine one for about a hundred quid (70 amp). He's also offered to sell me just the regulator to try that out..

[davidwort 0]

does sound more like voltage control than diodes gone down,

 

this looks OK for the money on e-bay

 

plenty of second hand ones, some from sharans etc, on e-bay cheap too.