haven't posted about trouble for a while... this isn't exactly a problem it's just something odd that i've noticed lately... considering i've had the car 2 n a half years i thought i'd mention it now!

when the alternator is under a constant load for eg- headlights turned on, when i then indicate, you obviously expect a "surge" so the headlights would dim a little as the indicators come on? and then get a little brighter as they go off... not quite.. i've always noticed the pulse but never realised until recently that when my headlights pulse, they actually get brighter as the indicators come on and they then dim as the indicators go off...? is this normal?

something else peculiar i noticed yesterday whilst driving in the rain, no headlights on but this time the constant load is the wipers! i had my wipers on, and this time i noticed that every time i braked (brake lights come on) the wipers would speed up!

is this normal? or do i have a bad earth or electrical issue somewhere?

the alternator pumps out a decent charge (around 14.8) and the regulator is only a couple of months old at most! replaced regulator and alternator bushes at the same time!

Try the other regulator.
Is the new one electronic?
Measure the voltage on the battery with and without load.
Then we will see.

It may be the regulator giving lower voltage all the time.

definitely the same voltage when under load and when not under load! both my previous two... regulators we're electronic solid state ones also! did away with the mechanical ones years ago!

i can't understand why things seem to gain power when another electrical item that draws current comes on... its the opposite of what should happen surely?

This must be a bad earth somewhere .
And when I say "somewhere "it is very hard to find.
maybe you should try and have a cable extension from the - of the battery to the body.
Only to try if this solves the problem.
Anyway, there must be a faulty earth somewhere .

The crappy bullet type connections all over the 2cv wiring corrode and the result is that the high resistance plays havoc with your electrics.It is so worth spending some time going over as many as you can find, especially those in the area of the headlamp bar, where they are more exposed to the elements.Taking them apart and cleaning them carefully until bight,replacing them with decent ones should also be considered.I reassembled mine a little smear of copper grease which helps with preventing corrision and also a good conductor.So be sure you don't use to much and keep the outside clean.I use to do this with all my motorcycles,which used right through winters with no problems.

Having cleaned these connections make sure your bulb holders are clean too, I found the front ones in a fairly bad state,when I changed my wings. I rewired all mine whilst I was at it.It's also worth running an extra earth to the body through a nice clean point,I used the battery tray fixings as they were new.

Good luck

definitely the same voltage when under load and when not under load!

Υou mean there is the same voltage with or without load?! How the lights shine brighter?
Try to clean /secure the earth point besides the battery.

ahh sorry understand more now, yes the voltage does go down when engine rpm drops to tickover with the headlights on, same as the wipers do slow down and the indicators are a little dimmer etc

Are you measuring these voltages yourself using a voltmeter, Joe? It would be interesting to see what the voltage is across, say, an actual headlamp is when the engine is revving a bit - and then with the indicators on.

If the voltage turns out to be actually quite 'normal' (ie: almost identical to the battery voltage) when the engine is revved and nothing else is on, then that would suggest the headlamp wiring is absolutely fine. If the headlamp voltage then goes up very slightly from the 'normal' range when, say, the indicators are used - so corresponding with the headlamps pulsing more brightly as you describe - then I wonder if this is, too, quite normal and just shows the voltage regulator is slightly 'over'-compensating for the increased load?

Voltage regulators constantly monitor the drain on the battery and charging system, and tweaks up the alternator output to suit the required load. It could be that it's doing precisely this - with aplomb...

In other words, if your headlamps are perfectly bright enough in normal use and just go slightly 'brighter than normal' when other devices are used, then this could all be quite 'normal'!

Possibly...

Joe,
a voltage regulator works by sensing the battery voltage and adjusting the voltage which it supplies to the alternator field winding, with the intention that the maximum voltage across the battery posts is no more than a pre-set value, usually 14.4 volts.

It seems to me that there is more resistance than there ought to be in the main feed wire which supplies your ignition switch, headlights, brake lights and so on, including the voltage regulator.
The voltage drop caused by that resistance will increase with any increase in the electrical load which that wire carries, hence your regulator is being supplied with a voltage which is less than battery voltage and adjusting the alternator's output to a higher voltage than it should be.

You can test for this fault by running a short lead direct from the battery positive post to the input for the regulator temporarily.
The connection should be made to the pin labelled D+ in this diagram of the regulator's connections.


Badge engineering? by slcchassis, on Flickr

If the test confirms that this is the problem, you'd need to strip the loom back to find its source, which is usually at or near one of the crimped connections...

ken

Right, I've had the engine rpm sat at a constant 2,500 at which charging is upto the usual 14.something with a multimeter across the headlight connections i had a steady 12V but then when turning on the indicators the voltage across the headlights then fluctuates upto 13.something each time the indicator lights come on!