93 Rover 218SD (charging) wiring diagram?

Main output wire (terminal B+ on alt) will go to battery, but may go via the starter motor. The best way to check it, is to measure the voltdrop along it, with the battery discharged a bit, and then immediatley after starting and with the engine revving slightly. Ignition light connected to D+ on alternator - going by your previous posts, it's working ok. The third wire, if connected to terminal W, it's an rpm sense (typically used for a rev counter), which it is going by your description.

Which alternator is it?

When my son bought his 218SLDT, it had a new alternator but still had an intermittent charging problem. Looking through the receipts that came with it, the local ex-Rover dealer had clearly had several goes at sorting it out. I eventually found that there was an open circuit in one of the leads to the alternator (iirc the field connection), but I couldn't find any obvious reason for it. So I ran another wire from the back of the fusebox to the alternator, and 16000 miles later, all remains well. I don't think there are any intermediate connectors, certainly no dreaded bullets, but for some reason electric was getting in one of the loom wire but not appearing at the other. The hardest bit was finding a suitably tidy run for the new cable.

Another way is to accidentally catch the end of a screwdriver on the terminal and the earth and see a small shower of sparks .. so guess that's a pretty strong 12V feed?

Check.

So the small round post rather than spade? Fairly thin wire ..?

No rev counter at the moment Moray.

Assuming that is simply an output from the alternator and it's getting it's 12V connection to the battery and exciter via the ignition light, are we simply looking at another dead alternator do you think?

All the best .. (and thanks for the feedback .. I'm getting pretty frustrated here not knowing what should do what (no HBOL etc) and therefore not sure what is important or how to test for it etc).

T i m

Erm ... good question Duncan. When we got it replaced we lost the bit of paper we wrote the info on, thinking that would be the last of it for a while.

FWIW .. (from memory) it's as long as it's round, has a black plastic end case .. a 1-1/4" x 1" finned ally part (reulator) on the end (flush with the surrounding plastic).

Looking at the end still, with it in it's normal mounting position .. there is a recessed 15A Lusas spade (male) at 12 o'clock, the larger output stud at about 3 o'clock and the smaller stud at about 8 o'clock. This one has a multi 'V' belt pully.

I'm in the missus cara atm but will see if I can see / read any labels when I get home.

All the best ..

T i m

Ok ..

Well with the alternator that came with the car it was ok for 3 years or so then started this not shoing the rev counter nor losing the ignition light intermittently (only over a week maybe before it bacame a hard fault. Changing the alternator cured the problem. Coincidence maybe?

So is that the wire from the ignition light or the third (thinner) one (I think we are sure the one with big wires is the output one) do you think Kevin?

Result! Is this the in car or in bonnet fusebox and what were you trying to pick up (as I don't have a wiring diagram for this thing). (ie switched live etc)

Evaporation? ;-)

Well that would be the least of my worries (as I had to make a loom from scratch when the missus and I built a kit car 18 years ago), it's more just knowing what is supposed to be connected to what and when.

I guess I would be more keen to start running new wires if I could prove that was definatly the fault (as it was proven to be with yours). If we know the ignition lead is applying 12V to the alternator and the output one is connected to a good batter (and there is a good earth) then I guess it's just a matter of knowing how important that third wire is (ie, if it *just* drives the rev-counter then I can live witout it!). If something elsewhere needs to sense the revs to keep the current flowing or something then it could be very important. :-(

All the best ..

T i m

FWIW I've just tried it with a 12V test lamp (.5W) and the same thing (light on all the time), if that helps pin anything down?

I rang the suppliers of the recon alternator and they are going to supply me another replacement and we will see how we get on.

All the best ..

T i m

Ok, I think it says ...

Valeo

??

All the best ..

T i m