Since I have installed the megajolt, 2 alternators have gone bust for me, the first seems to have shorted out or something as the alternator light remains permanently on even with ignition off. The second one blew today for me. Basically Alternator light remains on while running but when turning off the ignition the alt light goes out too.

Could it have anything to do with the crank pulley? Its smaller than the orginal so shouldnt that be better for the alternator?
I have set my rev limit to 6k while still playing around with the megajolt.

Both alternators were not new, but before I go and buy a reconditioned one or repair what I have, are there any suggestions or anything I may have missed?

here is a photo of my crank pulley:

VR sensor and trigger wheel 2

Unusual - the alternator will be turning slower with the smaller crank pulley so it should be giving lower output.

It might be a good idea to check that all of your earths are good, particularly the engine earth and the point where the battery negative is earthed. Bad earths can cause all sorts of strange problems.

Otherwise, maybe you've been unlucky...

[Edited on 3/7/08 by David Jenkins]

As David says , check your earth connections and also the block connector that goes into the back of the alternator. Another possibility is heat, I had problems with my alternator last year and have since fitted a heat shield between the alternator and the exhaust manifold . If the ignition timing is out it will cause extra heat in the manifold and engine bay . Vents in the nose/bonnet may help?

Very much as above First step is always to check the connector block at the rear of the alternator --- clean it properly and make sure the spade connectors get a clean bight.

Smaller crank pulley shouldn't cause a problem.

Is your alternator charging at all? Light on while driving suggests you have no charging. Meassure voltage at battery with engine on/off, should be significant difference. Pulley size have no influence on your problem.

Thanks guys, I will try both, heat shield the exhaust and check the earths. It is weird because this only happened after the megajolt was fitted..... and the fact perhaps that it is summer here and 35 deg outside...

i can see no reason why MJ should kill an alternator. you say both were not new so it is prboably conincidence that both have even succumbed.

depending on t he model - prboalbuy lucas - you can buy replacement parts - brushes, voltage regulator as those are the bits that normally go.

check you have good earth from alternator body to -ve battery - use a jump lead as a test between the two.

you can buy new lucas alternators - search for paddocks (LR spares) for about £ 30.

take the rear cover off and look at the brushes and check for free movement and wear.