10 replies to this topic

[gormless1]

If someone could help me please it would be much appreciated. I'm awfully sorry but i have to start with quite long story. I have recently acquired a 1987 Mini Park Lane and it went well until my Mrs (Sorry to all the feminists I mean wife) borrowed it and stalled it on a busy junction (left the choke out but it wasn't her fault after all how was she to know ? grrr) It jump started first time and after a ride around town I put it to bed. Next morning it refused to start showing all the signs of a deceased battery. After jump starting again I cleverly checked said battery with a voltmeter and it registered 14.3 when the engine was running but turning the engine off and trying to restart without success persuauded me to part with £37 to buy from my local halfords a new battery, (sorry it's so boring but I'm new to this, are you still awake?) Happy with my new power and hoping my Mrs (I mean wife) would be too paranoid to use my mini again I proceeded to traverse to work in my illustrious Park Lane where I decided to check with the voltmeter my new battery. To my dismay it only registered 12.27 volts. This left me a little perplexed so i decided to try and find more information on the internet and there was a mention on one site about ignition lights with relevance to batteries , alternators and charging of etc. Armed with this information I checked my ignition lights and they aren't working , I checked the bulbs and they are ok , so after all that I really don't know if
a) the ignition lights affect the charging of the battery
b) if so how can i find out what is wrong with the ignition lights
c) is the alternator shot and affecting the ignition lights
d) Am I over doing the punctuation (especially brackets)

ps could that flimsy circuit board thing be malfunctioning (behind the speedo/fuel/temp gauge )
everything else is sound as a pound except the reverse lights aint working but the bulbs are ok
enlightenment for any of these problems would be much appreciated
thank you

[Ethel]

The ignition light would come on if the battery isn't getting charged so in normal use it should only light up before you start the engine.

A good battery should put out just above 12volts if the engine isn't running. the alternator needs to put out a higher voltage to get the juice to flow into the battery so your 14v when running is fine. When cranking the starter the voltage will drop to around 9 volts because of the heavy load.

Yours sounds perfectly healthy it could be your 'little lady' just flattened the original battery cranking the life out of when it was flooded. If you've still got it, charge it up and you'll probably find you own a matching set of his 'n hers lead acid accumulators.

[Ethel]

The reverse lights are controlled by a switch screwed into the gear selector mechanism under the car - not the friendliest place for electrics so there's a good chance there's a loose or corroded connection or two.

[CharlieBrown]

What she/he said! (Is Ethel a Lady? - Im confused)

But congratulations on such an amusing thread!

[GraemeC]

If the ignition light does not come on at all (ie when you turn the key two clicks but do not start the car) then there is aproblem on its simple circuit. If there is a problem on this circuit the alternator will not sense the load and hence will not put out any charge.

As you've checked the bulb and it is OK then check the thin brown/yellow wire is connected to the alternator. If this is ok get a multimeter and check you have +12V to one side of the bulb with ignition on. If you do then remove the brown/yellow from the alternator and touch it to earth - now with the ignition on does the light light?

[gormless1]

If the ignition light does not come on at all (ie when you turn the key two clicks but do not start the car) then there is aproblem on its simple circuit. If there is a problem on this circuit the alternator will not sense the load and hence will not put out any charge.

As you've checked the bulb and it is OK then check the thin brown/yellow wire is connected to the alternator. If this is ok get a multimeter and check you have +12V to one side of the bulb with ignition on. If you do then remove the brown/yellow from the alternator and touch it to earth - now with the ignition on does the light light?

Thanks very much for all the replies to my post. Thanks and cheers to you GraemeC for your help , I carried out the tests you suggested and the redlight came on (but not the orange) just had to get some brackets in there ! Forgive me for living up to my moniker but does that mean my alternator is broken or is there something else ?
Again Many Thanks

[GraemeC]

If touching the wire to earth caused the light to come on then either the contact on the alternator is poor - give the terminals a good clean, or the alternator is goosed - in which case Iwould whip it off and take it to your local autoelectrician for testing/replacing.

The orange light is oil pressure - nothing to so with the alternator! This should come on with ignition and go out shortly after starting the engine (once oil pressure has been achieved).

[gormless1]

If touching the wire to earth caused the light to come on then either the contact on the alternator is poor - give the terminals a good clean, or the alternator is goosed - in which case Iwould whip it off and take it to your local autoelectrician for testing/replacing.

The orange light is oil pressure - nothing to so with the alternator! This should come on with ignition and go out shortly after starting the engine (once oil pressure has been achieved).

Thanks GraemeC, the terminals looked pretty good to be honest so I guess it must be the alternator. Sorry to be a nuisance but the orange light isn't coming on at all either do you have any ideas regarding this problem ?

[dklawson]

As GraemeC said, since the red light comes on when you ground the small wire at the alternator... you know the ignition switch and lamp are good. The failure of the light to operate when the wire is connected to the alternator can mean one of two or three things. You could have an extremely poor ground connection on the alternator. You could have open field windings in the alternator. Or, you could have a problem in the regulator circuit of the alternator.

As mentioned above, with the ignition off you should see between 12-13V on the battery. Once you start the car and have the engine idling you should see a 1V to 1.5V increase across the battery terminals. If you don't, you know that the alternator is not putting out enough to charge the battery. You should be able to pull the alternator and have it bench tested at an electrical shop.

The orange light is the low oil pressure warning. Like before, if you ground that wire on the sending unit and turn on the ignition the light should turn on. If it doesn't, first check and replace the bulb. If replacing the bulb doesn't address the problem, get out your volt meter and try to determine where along the wire to the bulb you are loosing power.

[Dan]

When you tested the ignition lamp, did you earth the wire in question to the engine block or the body? Do you have a mutlimeter? Check the resistance from the alternator housing to the body, there should be roughly none.

[gormless1]

Thanks very much for all the help it's much appreciated , hopefully one day I might be able to return the favour although considering my specialist subjects are beer and fags I very much doubt it but the offer is there ! I have decied to swallow the bullet as a mixed metaphoring friend of mine would say and buy a new alternator (probably will be posting for help on removing the old one let alone fitting the new one !) Crikey I am adding exclamation marks to bolster the brackets in my punctuation fetish! Hopefully the ignition light problem will be cured and I can then set about the oil light conundrum (probably when the Mrs/Wife doesn't seem like she's in the mood to give me the look of anger mixed with fury that says you're not messing about with that car again!) I was starting to get a little disheartened earlier when I realised the more I learn the less I know but things have picked up since then mainly due to the fact I managed to fit (if thats the right word) a lovely new RAC tax disc holder (you get one free when you join you know and I get a funny feeling I might be getting to know some of their employees quite well) to replace the old fashioned sellotape version !
I have to go now as I am having a punctuation attack (the only known cure is a beer and fag that's my story and I'm sticking to it)
Many many thanks for all your help
Cheers