6 replies to this topic

[Minigirl]

Today the alternator seems to have given in. Is there a fuse or anything on the charging circuit or a wire that could have disconnected anywhere? Thanks

[Minigirl]

been doing some reading and know what the problem is now I hope…. 

 

This thread states that you need a functioning charging bulb on the dash or the alternator won't charge the battery - 

 

http://www.theminifo...y-not-charging/

 

I removed all the bulbs on the dash to convert them to work with the centre clock while still using the car as a daily driver…. Never knew a bulb on the dash could cause a Mini not to charge the battery!!! 

[KernowCooper]

No bulb no exciter voltage for the alternator to charge, on the alternators normally used on Minis

[Minigirl]

thanks

 

Is it just me  or is that a bit of a silly design? If the bulb pops or something when in the middle of no where at night your a bit stuck… 

 

I guess a lot of people have wasted money on new alternators and batteries and rewiring just to find its a 10p bulb thats blown 

[CityEPete]

Well my morris 1000 has similar bulbs that are nearly 60 years old and still working well, that is the bulbs that are on for hours when driving at night rather than on for a few seconds before turning the key or when it is doing its job of telling you the car is not charging ie fan belt has snapped for example, I have never known one blow

 

As an electrician I should say Lamp rather than Bulb really, Lol

[KernowCooper]

Thats the design of Alternators I'm afraid and the charging light circuit, there are a few self exciting Alternators which use residual voltage within the magnetic field, but they are few and far between on cars, mostly on Plant and Machinery, but they now have  ignition light.

[Dan]

thanks
 
Is it just me  or is that a bit of a silly design? If the bulb pops or something when in the middle of no where at night your a bit stuck… 
 
I guess a lot of people have wasted money on new alternators and batteries and rewiring just to find its a 10p bulb thats blown

Yes and no. Once the alternator is running there is zero to negligeable current through the lamp so it can't really fail in use. You should be watching for what the warning lamps do when you start the car, it's in the driving test to know what basic warning lamps mean and almost all cars use them in the same way so there is no excuse really. You should be looking for certain lamps to come on and off in sequence when you start any car. When these alternators were first used it was a big step for Mini to use an alternator with both an internal regulator and internal warning light control, and this was the way to combine both inside one more reliable unit. Lucas alternators are by no means unique to Minis or even to BL. So yes it is silly for the possibility to exist that such a simple single fault will cripple the car, but equally if used properly it won't happen. However it is also a good thing and has a purpose. The lamp failure killing the alternator stops people ignoring a blown bulb indefinitely which helps prevent a more serious failure of the alternator, fan belt, water pump etc going un-noticed in the future and those are more likely to happen while driving. So the lamp not lighting when you turn the key can point to serious failure inside the alternator, or it can be a blown bulb. Either way it needs to be checked. As for people wasting money, guessing or assuming you know what's wrong will almost always result in buying the wrong parts. The answer is RTFM! And the same goes for modifying the car without really understanding what you are changing.