new alternator. still not charging right :(

[grainge231]

I fitted a new alternator a few days ago. All was going well, until i noticed warning lights come on again. The first couple of days after fitting it the voltage was 12.5 at idle, 13.7 at around 2000rpm, and 14.5 at 5000rpm. Also changed the 120amp alt fuse. Now driving it for a couple of miles the alt warning lights are back on and the 120amp slowblow fuse has started to brown up, all connections to the alternator are tight, aswell as connections to the fuse. Im now only getting a 11.5 charge rate, any ideas welcome!!!!

[SID]

Had same . My alternator die , so get 2nd hand - after 1 day light on . Get brand new - problem gone .

[mrturbotom]

Should charge the same throughout the rev range, I got a 120amp alternator and charges 14.8v at idle with everything on.
I'd also check the wiring to the fusebox from the alternator as it corrodes

[abovetherim]

I'm sure someone like peter will pipe up soon but you need to check the output on the 3 wires into the plug. IIRC you should get 12v on all 3 with the ignition on. If you get zero on any of them then trace the wire back to the fuse box and check applicable fuses, relays and continuity of the wire from there to the plug. First suspect would be the black and yellow wire. However if you are still getting some charge at higher revs and none at idle then this does point to the regulator in the alt.

[Driftlimits Performance]

U may have 12v doesn't mean you have the required amps

[grainge231]

Thanks for the replys guys, this is an old alternator which i stripped, cleaned and reassembles with new brushes and regulator. I gues next step is to check he 3 wires on the plug, making sure they all have atleast 12v each before pluging into the alternator yes? And check earths. If all these are good ill have to shell out for a new alternator i guess

[grainge231]

If anyone knows the locations of earths to check i would be appreciated,

[Shmed]

Have a look here http://www.imoc.co.uk/forums/viewtopic. ... ator+earth

Peter has gone through the wiring for someone else. It might help.

[grainge231]

Thanks dude. Thats really helpfull. Will use that guide to start eliminating what it could be

[Shmed]

Thanks dude. Thats really helpfull. Will use that guide to start eliminating what it could be

No probs. Good Luck

[grainge231]

So battery voltage is 12.5.


Alternator plug wires

Black&yellow 12.3
Red&white 12.3
Yellow 11.5

All fuses are fine. Is theres any earths i should check? Or has this all boiled down to the alternator?

[grainge231]

New alternator should arrive today, hopefully this will fix the problem.