75ZT Community

I have a s/h working alternator from a Rover 75 CDTi classic saloon (low spec but that worked well) but not sure if this alternator is good enough to fit on my present CDTi because I am not sure if the slip rings are too worn or discoloured? From searching the web the copper slip rings should not be discoloured. If so there is no point in me changing the regulator which includes new brushes? Although the alternator works it appears to worn out to last long? I have ordered a new alternator

What do the contact surfaces of the old brushes look like? They should have a shine on them and be free of any damage with no evidence of burning - burning results in a matt/charcoal effect. Given that you mentioned that the alternator is working I suspect that all will be ok with the brushes. The residue on the slip rings looks normal, I would expect to see it as part of the lubricating film which forms.

Without any lubrication carbon brushes will wear quickly and possibly burn sooner rather than later. At low altitude the key component in the lubrication is the moisture in the air, at higher altitudes there is little moisture in the air so in aviation special film-forming brushes are used to compensate for the lack of moisture.

Thanks WillyHeckaslike. Apart from fixing I am interested in how it all works. I haven't piloted, repaired or owned an aircraft but had many a conversation with those who do. As an air passenger I have taken off more times than had landings.

I place photos in case it is useful to see what a more worn but working set of brushes and copper slip rings look like. By comparing these less worn photos below with the worn but working alternator above

A previous owner had fitted a 3 pin alternator (usually for Rover 75 CDTi of 2003 and earlier to my 2004 CDTi 2 pin wiring loom. It was the 3 pin alternator was on the car when the battery light came on and stayed on.

The less worn brushes and copper slip rings from the 3 pin alternator are in the attached photos below.

I have a spare worn but working 2 pin alternator which is in the photos in the first post above.

I am wondering what difference the correct 2 pin alternator will make when fitted because the lead from the alternator to the ECU (Engine Control Unit) seems different.