Thread: alternator 300tdo

you need to alter the pulley on the one from MR as a general rule.

take off old one and fit to new one, very straight forward.

when i got my 100amp unit from them it was in a denso box but had the marelli chassis ...

Originally Posted by weeds

started the defender this morning and she was a little sluggish, thought that was strange

got to work and checked charge rate at the start battery, no charge, checked aux batteries, no charge, pulled the wires on the back of the alternator, no output.....should have my alternator light been glowing??

no markings on the alternator but i'm pretty sure its the standard 65amp ? jobbie, is there other checks i can do prior to dropping around to an auto elec??

is it reaaly worth getting a 65amper rebuilt when i have two 100amp/h deep cycle batteries fitted

need an alternator reel quick as i'm going camping on sat....did a search and found a few differant options, my local parts supplier has a brand new disco 100amper on the shelf that they tell be bolts straight up

i did notice the charge light flicker every now and than a month or so ago, no charge light on the last couple of days

just discovered one of the bad points of having a manual dual battery isolator, two 100amp/h deep cycle batteries and a solar panel....the alternator could have failed ages ago and the solar panel has been looking after me

I just replaced mine with a UniPoint 70A, $240 with my old pulley. Your light should have been on. Mine was. Otherwise I wouldn't have known.

Originally Posted by incisor

you need to alter the pulley on the one from MR as a general rule.

take off old one and fit to new one, very straight forward.

when i got my 100amp unit from them it was in a denso box but had the marelli chassis ...

thanks inc

Originally Posted by wally

I just replaced mine with a UniPoint 70A, $240 with my old pulley. Your light should have been on. Mine was. Otherwise I wouldn't have known.

ummm wish the 100amper was a bit cheaper

am going to drop into the auto elec on the way to picking up the alternator to see why the light did not come on

Have you checked the charging warning lights bulb. If the bulb blows, the alternater wont charge and the bulb wont glow either. No light=no charge. Current must flow through the bulb to start the alternater charging. Does the light come on when you switch the ignition on?

Originally Posted by incisor

you need to alter the pulley on the one from MR as a general rule.

<snip>.

Only with an early 300Tdi Defender, the later ones had the same size pulley as the Disco (53mm)

Originally Posted by wally

I just replaced mine with a UniPoint 70A, $240 with my old pulley. Your light should have been on. Mine was. Otherwise I wouldn't have known.

So it was just coincidence the alternator failed when you fitted the new instruments ?

Originally Posted by jimbo110

Have you checked the charging warning lights bulb. If the bulb blows, the alternater wont charge and the bulb wont glow either. No light=no charge. Current must flow through the bulb to start the alternater charging. Does the light come on when you switch the ignition on?

According to my manual

The generator system provides for direct connection of a charge (ignition) indicator warning lamp, and eliminates the need for a field switching relay or warning light control unit. In the event of bulb failure, an 'exciter' voltage is supplied through a resistor, wired in parallel to the bulbs, ensuring that generator output is maintained. The lamp should be checked regularly

So I've learnt something on both counts.