Outer Limits 4x4 Board

My alternator is not charging when I first start the car until i rev it over 3000rpm, then the charging voltage varies from 13.8 to 15.1. 15.1 being most of the time when driving under normal conditions. Is 15.1v too high?
Will this cook my batteries? How do i test the batteries? The car is a 89 swb gq patrol with an aftermarket oex enduro 70a alternator. Thanks in advance for any replys.

Sounds like the regulator is cactus. 15.1 wont cook the batteries in the short term (as long as they rent gels), but its no good having it only charge over 3000rpm

they are lead acid batteries, and once it gets over 3000rpm it starts charging at any rpm. It's like it needs to be excited by revving it then its ok until you turn off the engine. Can you replace regulators? Thanks

Does your charge light on your dash work? That's the traditional way to provide the excitation current to start charging.

regulators can be changed. Only thing will be if yours is internal or external to the alternator.

Thanks for the replys, i've never seen a charge light on the dash? I don't weather you can test it or not?

Thanks for the replys, i've never seen a charge light on the dash? I don't weather you can test it or not?

The charge (or battery) light should come on when the ignition is on. If it doesnt then something is wrong, wether its blown globe, wiring or reg/rec.