Alternator Light on, charging problems

[wallwall100]

Hi, My alternator light came on several days ago, so I decided to purchase a new alternator thinking this would resolve the problem, after replacing the new part the light is still on ;( after reading some previous posts I then tested the voltage to the battery with a multi meter =12v not 14 ish. My bus is an original 86 westy 1.9dg running all standard duel charging and setup etc, the alternator is an 90 amp, I also checked all earth and connections all look good and original, according to the multi meter its not charging the main battery or leisure batt. I was wondering if the standard westy split charge relay if failed would stop the alternator from charging the batteries. Any advice appreciated. Thanks

[ewenmaclean]

Hello,

if the new alternator is definitely ok then I'd check you have the exciter wire (blue wire) connected properly to the alternator - see if it has +12V at the alternator before you turn it over. I've had alternators in the past which needed some revs before they started charging - does it charge at all when you rev it up? Also check you have 12V at the alternator main terminal (B+) before turning it over.

Hope you figure it out

Ewen

[82JEW75]

When I fitted a new alt to my Skoda Favorit, the instructions required two of the terminals to be momentarily shorted in order to polarise the alt, or something along those lines (it was ten years ago). Check the instructions or haynes for something like this?

[andyb]

Use a voltmeter to check the alternator output at the battery - if thats fine then its probably a short in the blue wire to the dash.