charging issues

[magicdeo]

Hi, my 4JB1 rodeo has recently started staying at about 12.8v after the first start of the day for about 2 minutes before it goes up to 14v. The other night I noticed that it had dropped to 12.9V for maybe 3 minutes or so before increasing to 13.5V and stayed at 13.5 for 45 minutes. The next morning it was back to 14 - 14.1V. It normally runs at about 13.9 or 14 at night with lights on. No idea how old the altenator is but I know it hasnt been touched for atleast 200,000kms. Whats the best bet, new brushes/new alternator/full rebuild of old one? Just looking for ideas.

Cheers

[geeves]

What does it do if you give it a quick rev when it sticks low? Based On the info so far my money is on the charge relay although the alternator might need a service

[magicdeo]

No, the volts don't change with revs at all. The charge relay isn't very old.

[geeves]

Are you rellying on the volt meter in the car or a good multimeter. What you are saying is that it sounds like the alternator but its better to eliminate all other options first

[magicdeo]

I used a fluke multimetre for all testing.
I put a new altenator in today (OEX HXA081) and its charging perfectly. The problem I have now is that the motor wont turn off with the key. Anyone had this issue? All I did was put a new altenator in.

Thanks

[geeves]

genuine or genuine equivalent alternator? I have heard of this problem when people fit other alternators where the aircon sits. A diode fixes it but it shouldnt occur if oem used