Thread: Flickering Lights, bouncing ammeter - reg or alternator faulty?

There could be 3 common issues: regulator, rectifier(diode pack) or brushes as long as there is output but fluctuating, usually if the winding is gone there will be no output from it... depending on the modell there are full repair kits available

Start with the simple stuff.... earthing. On your battery end, the engine end, to the body, then the hot lead to the starter motor, alternator wires...

Is the flickering regular or random ?
Changes rate with different engine speeds ?

What vehicle is it and how old is the alternator?

thanks - i have checked the earthing etc and that all seems to be fine.

the vehicle is 1995 Discovery tdi.

I have an ammeter fitted and the fluctuation appears to be have a constant frequency regardless of rpm, that said it is worse intermittently - by this i mean that the fluctuation with the head lights on is always there but the intensity can vary.

also i have noted that the ammeter sometimes is stable when charging i.e. sits at several amps then other times (most of the time) it bounces wildly all over the place.

the problem has been there since i bought the car about a year ago but is getting worse.

what has exacerbated the problem is i fitted dual fans, electric water pump and electronic controller and it goes to fault mode whenever the fluctuation is worse which looks like a voltage problem?

Jim

Originally Posted by sierrafery

There could be 3 common issues: regulator, rectifier(diode pack) or brushes as long as there is output but fluctuating, usually if the winding is gone there will be no output from it... depending on the modell there are full repair kits available

are repair kits available online? i can only seem to find alternators complete out of the uk

I am interested in this as my series 111 has the same problem 75 amp bosch alt . Amp meter needle stable for about 5 min after starting then starts to bounce at this time it seems to be charging ok volts meter is ok and right on 13.8

Most cases like this are signs of regulator failure. The trouble is usually finding a regulator to suit your particular model of alternator. I've replaced loads of Bosch ones over the years for this problem.