BigRed

Driving home last night i noticed that my headlights where going up and down in brightness so i switched the ICE off to see if this was the problem, but it continued.I have noticed this a few times recently. I got back to my garage and left the car ticking over with no ICE on and the revs were not steady , it was as if there was a large load going onto the alternator and pulling the revs down. There has been no battery light come on as if it was a blown alternator. This fault has a regular cycle on and off about once every 5 seconds, i have a split charge system with a battery in the boot and under the bonnet, i am now thinking that there could be a fault in this somewhere as the amps did cut off a couple of times on the way home as if an undervoltage fault but have never done it before , i have not had chance to check anything yet but any advice would be welcomed.

BigRed