Pulsing lights?????

[bhpjon]

Mornin' all, (note to self) i must get some sleep at some point, does anyone know why all of my lights are pulsing bright/dimmer/bright/dimmer etc i have just done a rebuild so i can't guarantee i have everything back in it's correct location, any ideas please?

[shpub]

Usually a faulty alternator pack causing bad voltage regulation or bad earths.

Edited by shpub on Monday 24th September 09:09

[crackedfinger]

Does it follow the surging revs of the engine or pulse independently?

[That Daddy]

If its any help,i had the same problem more noticable on idle,alternator was giving fluctuating output,new one corrected fault,as the others said check your earths 1st, you may get lucky.

[bhpjon]

crackedfinger said:

Does it follow the surging revs of the engine or pulse independently?

I think it's pulsing indepentantly, but difficult to be sure?

[bhpjon]

shpub said:

Usually a faulty alternator pack causing bad voltage regulation or bad earths.

Edited by shpub on Monday 24th September 09:09

There is a vacant spade connector on the back of my alternator and a wire that doesn't follow the info in the bible, could this be anything to do with it (the wire is white and grey) and is in the right vicinity. When i was putting it all back together after rebuild, a lot of the sticky labels i had put on had fallen off so i had a group of mainly white and black wires which i have attached to the coil, leaving this white and grey one over? The car doesn't seem to be pulsing on tickover is that the case with faulty alternator? cheers

[spend]

Stick a voltmeter in your cig lighter socket (or any handy place) and see what voltage is being generated, under 12 your alt is not working ~ should be @13.8v IIRC. There should be a spade on the back of your alt that gives 12v when the ign is switched on to start the field coils (check this also with your DMM) which is connected via the ign warning light on the dash (and usually a resistor in parallel so the alt gets kick started even if the bulb blows).

You really need to work out if you have a problem with the alt or the lights.

Dave

[bhpjon]

spend said:

Stick a voltmeter in your cig lighter socket (or any handy place) and see what voltage is being generated, under 12 your alt is not working ~ should be @13.8v IIRC. There should be a spade on the back of your alt that gives 12v when the ign is switched on to start the field coils (check this also with your DMM) which is connected via the ign warning light on the dash (and usually a resistor in parallel so the alt gets kick started even if the bulb blows).

You really need to work out if you have a problem with the alt or the lights.

Dave

Thanks again Dave, i shall get on with this tomorrow!
P.S will do tonight now, had a busy couple of days!!

Edited by bhpjon on Wednesday 26th September 12:44

[bhpjon]

spend said:

Stick a voltmeter in your cig lighter socket (or any handy place) and see what voltage is being generated, under 12 your alt is not working ~ should be @13.8v IIRC. There should be a spade on the back of your alt that gives 12v when the ign is switched on to start the field coils (check this also with your DMM) which is connected via the ign warning light on the dash (and usually a resistor in parallel so the alt gets kick started even if the bulb blows).

You really need to work out if you have a problem with the alt or the lights.

Dave

I measured the voltages tonight and sure
enough there is 12.86 v at the battery, no ignition, then 14.20-80 on
tickover (although i'm not sure it should be fluctuating all the time) and similar under load so it seems that the alternator is working
ok and i will wire up the mysterious cable mentioned in the other post to see if is the source of my pulsing problem

[spend]

.6v fluctuation seems a bit high to me, could be the alt's rectifier tiring. Did you try it with the heater, fans & lights on? Try loading the alt & see if the fluctuation gets worse.

Dave

[That Daddy]

Take off the fanbelt and see if the lights still fluctuate,dont run for long though(it will overheat)try to do it when the engine is cold,Spend is correct that reading should stay steady when chargin,as i said earlier mine was doing the same thing but on idle and the output from my alternator was fluctuating on idle beetween 13.4 an 14.8 Volts as i remember.

Edited by That Daddy on Thursday 27th September 12:51

[bhpjon]

spend said:

.6v fluctuation seems a bit high to me, could be the alt's rectifier tiring. Did you try it with the heater, fans & lights on? Try loading the alt & see if the fluctuation gets worse.

Dave

Yes blowers,lights were on, fluctuation stayed about the same?

[bhpjon]

That Daddy said:

Take off the fanbelt and see if the lights still fluctuate,dont run for long though(it will overheat)try to do it when the engine is cold,Spend is correct that reading should stay steady when chargin,as i said earlier mine was doing the same thing but on idle and the output from my alternator was fluctuating on idle beetween 13.4 an 14.8 Volts as i remember.

Edited by That Daddy on Thursday 27th September 12:51

Ok will give this a go , but as you say may well be worth getting rectifier looked at?

[spend]

Maybe its not fluctuating too much then, does it do it on Main beam as well - different filaments & relay used for them.

Dave

[bhpjon]

spend said:

Maybe its not fluctuating too much then, does it do it on Main beam as well - different filaments & relay used for them.

Dave

Will try that too, cheers Spend!

Edited by bhpjon on Thursday 27th September 14:50

[bhpjon]

bhpjon said:

That Daddy said:

Take off the fanbelt and see if the lights still fluctuate,dont run for long though(it will overheat)try to do it when the engine is cold,Spend is correct that reading should stay steady when chargin,as i said earlier mine was doing the same thing but on idle and the output from my alternator was fluctuating on idle beetween 13.4 an 14.8 Volts as i remember.

Edited by That Daddy on Thursday 27th September 12:51

Ok will give this a go , but as you say may well be worth getting rectifier looked at?

If they don't pulse any more that means it is definately an alternator fault, doesn't it? (Pardon the stupid nature of question)