Not charging ..

There is either a major fault with the leads or connections or the alternator is faulty. I remember chasing a fault on a fiesta once, symptoms were not charging sometimes !! Changed the alternator for a checked to be working one, worked for a few days, then stopped charging, changed alternator for a known good secondhand one, worked ok for a few days, aaaarrrgh. Eventually I discovered that there is a join in the charging lead between alternator and battery and it had a bad connection there.

So, in your case I would wire the battery power side of the alternator completely seperately straight to the battery, add an earth wire for the alternator straight to the battery and retest it, that way you have eliminated all the wiring loom stuff, the warning lamp sound like it is operating OK, so you can ignore that.

I bet that was a "YES" moment!

Good idea. I must admit (now you have me thinking further) that I haven't actually measured to see if it is (or isn't) actually charging this time but the observations I have made so for (headlights not picking up as I rev from tick over at start) and the previous experiences suggest it isn't.

Indeed, unless there is something we have missed? :-(

I guess engine block > chassis > battery -Ve AND battery +Ve > starter solenoid and general electrics are also ok as the car in general is working ok?

I am due to pop it into my mates garage this week to fit a exhaust flange gasket (they didn't have one when we took the front section off to weld a few weeks ago so we just used compound) and I'll do as you suggest re the wiring at the same time.

All the best and thanks again ..

T i m

Maybe. How's the alternator earth?

It's not the old favourite dodgy connection on the earth strap is it?

Well, assuming the alternator is firmly bolted to the block via it's steel brackets and the block is earthed well enough to take a couple of hundred (?) amps when starting I think it's probably 'good' Duncan?

Assuming my understanding of your suggestion and my logic are correct of course! ;-)

FWIW I will check / clean all the earth paths again (I changed the -Ve battery > Chassis strap last time because it looked 'iffy').

All the best ..

T i m

As I mentioned to Duncan I changed the battery -Ve to chassis strap the last time this happened Paul (all mating surfaces cleaned bright and protected with grease afterwards). I think it was actually ok (electrically) but as they are cheap I replaced it anyway.

Maybe I'll remove, check, clean all the others (especially -Ve to block) and see what happens.

All the best ..

T i m

They're good, assuming the alternator hasn't got some vibration damping mounts (Vauxhaul used to love confusing the issue with those)

No, this is a 15 year old Pug powered diesel Rover remember!

Mind you, I'm not complaining, 4 years motoring for purchase price of £100 plus a set of tyres, an alternator and a few other bits over the same period.

And it's paid for those bits by still doing ~50 mpg, twice what I used to get out of the Sierra Estate (although I still miss the Sierra if only for the l o n g guttered roof and my Thule roof-bars [1]). ;-)

All the best ..

T i m

[1] Handy for the 16' canoe, 5m lengths of steel box, the sailing dinghy mast ... ;-)

So, I tested the output cable from the alternator today and that's good n solid (two heavy duty cables run in parallel).

We know the cable from the ignition light is ok as that goes on and off as expected but what is the third (thin) cable connected via a small ring connector?

Is *that* the exciter and also rev counter feed (rather than the ignition light cct doing either)?

All the best ..

T i m