Dashboard lights problem

[magpie]

i think you just self diagnosed .

[Brianmoooore]

Plenty of life left in those brushes (the usual problem), but that doesn't mean the rest of the regulator is good.
Could also be a problem with the diode pack in the alternator.

[mrLEE30]

do you have a voltmeter?

If so replace everything and start the engine, hold RPM at about 1500-2000rpm. all electrical things turned off

set meter to read volts DC (DCV) and check the voltage at the + and - battery terminals. you should get about 13.5-14.0Volts.

higher then this (i.e 14.5 votls) then the regulator is likely to be faulty.

lower then this (less then 13.5V) then turn on the headlights, rear demister and fan motor

if it remains at about the same lower voltage then investiage the regulator
if it drops even more then suspect the alternator.

You can replace the diode or alternator brushes, you do not need to replace the whole thing.

[Brianmoooore]

A problem with the above is that if a diode has failed there may be a large ripple (AC) component superimposed on the alternators output, and this is likely to upset the readings on cheap multimeters, giving false results. An oscilloscope is what's really needed.
Any chance you can borrow an alternator from anywhere? Ideally, try the regulator pack from that fitted to your alternator, because that's quick and easy to do, and if that doesn't help, change the alternator over.
Diodes can be replaced, but not really worth doing with the availability of second hand alternators. Just fit it with whatever regulator has the best brushes.

[Brianmoooore]

A Fluke isn't the cheap multimeter I suspect most on here have, so might be worth a try, although I know the readings on mine were meaningless the other day, when I tried to check the output of a 12 volt PSU that was a 100kHz sort of square wave!

[Brianmoooore]

Fuse 29? That's for the LH front fog lamp!

[kieran325]

I had this problem several weeks back, same lights etc....

I replaced the voltage regulator and the lights went out, I don't normally have my sport out at night but same lights are lit but very very dim, you can't see these lights during daylight.

I might just buy a new alternator and have done with it

[Brianmoooore]

Are you claiming that fuse 29 blows when you turn on the headlamps and the foglight switch is off?
If the foglight switch is already on, this is possible, but if not, you have some very strange wiring!

[kieran325]

I checked all fuses and all was fine.

It was working perfectly in the afternoon and I then went to move it in the evening and all hell broke lose.

I did replace the regulator and like I say the lights went out but I'm still not convinced.

It normally sits in the garage on trickle charge and for the past week I've not used the trickle charge and hopefully if the weather is dry then I'm going to whip it out and see if it starts!

[Brianmoooore]

So it was a diode pack problem then!
This could well have finished off your headlamp bulbs.
Heat knob should be illuminated, and this bulb is dead easy to change IF you have an analogue clock and not an OBC.
The front bezel of the clock just levers off, then the clock can be removed out of the panel by squeezing the obvious tabs. The bulb is immediately below the clock aperture.

[Brianmoooore]

I wouldn't bother refurbing the old alternator. Diode pack failure is rare, so if you want a spare, you'd be better off finding another second hand one.
The only "refurbing" 90% of E30 alternators need is a pair of carbon brushes, which come as part of the reg. pack.