Battery Charging problems, cooked alternator.

Hi All

C3 2003 1.4 Petrol :

Fitted a second hand alternator thinking that I had alternator problems as there seemed to be a smell of burning coming from the old one.
Reset the ECS as per instructions found on the web. But still no charge voltage when car running just 12 volts.
I did read a topic that mentioned it may be the Signal from the ECS ( the white cable ) on the alternator ?
I have ordered an engine diagnostic scanner to see what faults may be in there.

Any ideas

Regards John

Hi John, I did see your post on this topic.

Have you tried getting the revs up to 4k with the volt meter attached as was suggested by the AA man for ukyorks, it may help track down the problem.

Alternators do fail, so maybe your replacement is faulty too? Alternators are easily tested on the bench, maybe worth having them both checked.

Was the burning smell tracked down to the alternator? if not then it could be the plug or wiring, this needs inspecting. Also its worth checking the connections are nice and clean as a corroded connection can cause no charging.

The wire on the big connection (the one with the nut) is known to go bad (high resistance), its worth inspecting and testing this (for resistance).

Can you get the meter on the back of the alternator power nut with the engine running and check for volts to earth?

Check for a signal (volts) on the white wire too.

Thanks Arfur Dent for the reply.

I have run the car @ 4000 rpm but the voltage is the same 12.5 volts @ the battery. This is the same as the output from the alternator. I did clean the connections on the second hand unit before i fitted it . Connections to starter motor also checked and negative from battery to car chassis all seem ok.
what would be the best way to check the resistance of the alternator ?
What voltage would be on the white cable ? Is this an enable signal from the ECS or just a OK to the ECS ?

Regards
John

Tailspin wrote:This is the same as the output from the alternator.

Where did you measure this? Was it right on the stubby bolt of the alternator output or somewhere else?

Tailspin wrote:what would be the best way to check the resistance of the alternator ?

I would take it to someone who has a test bed or bench set up to test for an output. They will connect up a 'dummy car' to it and spin the input with a motor. I don't think just checking a resistance of the alternator is going to do you much good.

Proving the alternator good or bad is going to save a fair bit of time looking at the wrong place.

Arfur Dent wrote:The wire on the big connection (the one with the nut) is known to go bad (high resistance), its worth inspecting and testing this (for resistance).

I mean testing the resistance from the nut on the alternator output to the other end of the wire at the battery live - battery disconnected

Tailspin wrote:I did clean the connections on the second hand unit before i fitted it .

Its the connection of the wire in the car to the ring under the nut on the alternator that needs inspecting/testing, rather than the ring to the alternator, And the plug that has the white wire needs checking.

The alternator white wire is an output to the ECU, so the ECU can measure the load on the alternator. (DFM or Digital Field Monitor terminal)


There is another wire that is connected to something to produce and excitation current to get the alternator to start generating some current. (L terminal)
DFM goes to a computer (petrol engine - engine ecu - white wire, diesel engine - BSI - green wire), but I don't know where the other wire goes

Could the other wire be the Rev counter sensing wire?

jbz2079 wrote: Could the other wire be the Rev counter sensing wire?

I think with the computer controlled (ECU) engines in the C3, the rev counter signal comes from the engine ECU, probably derives from the crank sensor.

Did you manage to get to the bottom of your issue? I have the very same issue and have tried everything.

On the white cable to the alternator I get 11.6 volts. I also noticed the pin for the connector on the plastic cover of the alternator doesn't go anywhere and does not touch any of the metal parts of the alternator.

Does anyone have a fix for the none charging issue?

I have the same problem with my alternator, I replaced it with a second hand one and this was just as bad, there must be something to cause this, as I have only just got my 2003 Citroen c3 mk1 1.4, I have no idea where to start on it, there seems to be so many Citroen owners with the same problem we have but not many answers

Charl1310 wrote:I have the same problem with my alternator, I replaced it with a second hand one and this was just as bad, there must be something to cause this, as I have only just got my 2003 Citroen c3 mk1 1.4, I have no idea where to start on it, there seems to be so many Citroen owners with the same problem we have but not many answers

Hi Charl1310,

I suggest you list what problem you had that caused you to source a replacement alternator and then describe what you did further identify the problem.

Tailspin wrote:Fitted a second hand alternator thinking that I had alternator problems as there seemed to be a smell of burning coming from the old one.

This was the problem identified by the poster.

You can start your own topic here if you want to ?