Alternator ?

[KevD]

Replaced the battery after it had sat for about 4 weeks ( I should know better ). Started straight away but with horrendous squealing and light smoke . 99% sure the alternator had seized and then freed itself as it was suddenly OK. Or is was suddenly fubard.

Drives fine but battery light on the dash is on solid. Is it a hangover from battery change or is alternator scunnered ?

[robin]

If the battery light is on solid then either the alternator is knackered or the cable feeding it has fractured.

Given your reported symptoms I am tending towards the former, sorry ...

Cheers,
Robin

[KevD]

I kind of knew the answer already I'll charge it off battery charger and limp to the garage to get it replaced

[robin]

I might have a second hand one for an S1 if you want it - kind of think if you're paying a garage to fit it you should buy a new one, though, as the labour cost is probably similar to the alternator cost.

[KevD]

£40 an hour is worth it to not remove all the skin off my knuckles, battery is bad enough and I need to service jeep ve just bought as well .

[robin]

Agreed - I have no time to wield spanners these days and am happy to pay to get it done for me Just saying that once you've paid for the labour it's probably a false economy to fit second hand parts unless they are very nearly new!

[KevD]

Yeah refurbished would be fine but may as well the pay the extra. Second time it's went in last 3 years, probably due to standing outdoors too long

[robin]

Or maybe just rubbish parts! There's really no excuse for it failing twice in 3 years if the wiring is intact - there is a fault whereby the control wire (the same one that lights the charge warning light on the dash) can be fractured or loose such that it causes intermittent contact - in this state the alternator goes from charging (wire connected) to not charging (wire disconnected) rapidly whilst the engine is running - the regulator pack doesn't like being asked to stop charging whilst 20+ Amps are flowing through it and eventually fries itself. There is also the problem of heat - if you don't have all the alternator heat shielding fitted then you can cook the alternator. Neither of those faults sounds like yours, though, so I wonder if the part you started with wasn't good quality.

[Stephen]

I have had 3 seize on me they tend to destroy the casings too

[robin]

Isn't that a sign of either something else wrong or rubbish parts?

[Stephen]

Robin I don't think it's either. There may be a poor application issue though.
The armature seems to become rusted to the stator if you leave the car sitting. When you start it sometimes it breaks free but often the belt shreds itself and the twist it induces seems to break the vent fin leg parts at the pulley end of the aluminium casing.
The initial rusting issue, I would imagine is a result of the open engine cover allowing water in and the heat built up between the engine and the bulkhead from the exhaust possibly affecting the corrosion resisting abilities if the alternator internals.

[KevD]

Rusting / sticking issue when its sat is problem here. I usually have the soft top leather bag resting over engine but forgot.

Just to amuse me the jeep I bought had a failed battery and now... A dodgy alternator I think! Bought a second hand one for that £50, judging by the YouTube video its 20 mins to change. If only access to the Elise was so easy!

[Stephen]

The Elise is not too bad.

[Stephen]

Be careful buying a new alternator as they come in 2 amperages if my memory serves me it's 65A and 85A. Both look the same.

[Corranga]

Probably a bit late to the game, but there is an eBay seller that does them pretty cheap. New (well reconditioned but they all are..) Denso recond unit (mine was in a denso box but is a magnetti marelli alternator) for about 70 quid