The car failed to start one morning last week. My partner got a lift into work and I popped over with a c-tek batery reconditioner. We charged the battery over night and the car was fine. I blamed the worn electric tailgate latch that I had adjusted again.

The car has had a missaligned tailgate and worn the latch over a number of years, we are now having to deal with it as the new owner. If it continues to be a problem I'll replace it with a pattern part, these are all over ebay and Aliexpress - this normally means it's a component knowm to fail and the Chinese are doing their part. If the latch fails to lock in for the microswitch  the module doesn't go to sleep and drains the battery over night.

Anyway....

Commuting to work my partner noticed the car displaying the all too common 'charging system error workshop' or something like that. She works at a new car import centre and the workshop had a look at it, they confirmed the battery was in a state of discharge and that the alternator wasn't charging.

Now I had performed the same check the week before only to have the opposite result, the battery showed around 85% health and the system was charging at 15v, infact after letting it idle for half an hour the stop start kicked in.

So tonight I had another look, first I checked continuity across the alternator live and the battery- all good, no blown fuse

Checked for any unusual noises and then the freewheel clutch, the alternator uses a spragclutch pulley which improves general smoothness of the engine, I think there are videos on youtube showing the difference with or without a freewheel. The spragclutch had lost all drive and was failing to spin the alternator, I have never seen that type of failure before! I'll take a video of it and post it before I change sprag for a new one.

2018 Edge sport 80000miles.

Darren

 

I still find the way AI writes to be very strange. 🤔

Even stranger that another AI bot liked the post 🤣

Even if it is a bot, funninly enough had similarish to this myself (without the dashboard errors/flat battery). Had the car in 2 weeks ago to replace the seized alternator pulley. Engine was rough as nuts on idle but back to normal now £300 later!

I'm not an AI. But I am a mechanical engineer, one way sprag bearings are not a new thing, they've been around for years in the industrial sector, I always thought 'new style alternators' worked with an electrical clutch, or modules that control the alternator exciter to reduce the load on the engine and increase efficiency

D

I'm fitting the freewheel pulley, the dealer is paying for the part. I'll video the before and after next week

Dealership asked to see a video, I've edited to shorten, but look at the internal fan to see what thel alternator is actually doing.

 

As you say (Good test) as the freewheel (with sprag clutch probably based on ball bearings in a track that grips one way and locks the other- I'm an ex-engineer too!) definitely doesn't appear to be working.

The LIN Bus controls the charging output and the clutch is not fitted to all models for reasons I don't fully understand (its purpose is perhaps not wanting to drag alternator speed down and hence waste energy etc when engine decelerates quickly and other reasons as here?):

https://idpartsblog.com/2018/07/09/clutched-alternator-pulleys-are-important/

What a JOB!

Tried to change the pulley in the car 

1) with the alternator still bolted up, just not enough room to install tools

2) unbolted the alternator and tried to undo the pulley wheel- snapped the tool in the shaft ahh!!  This was my biggest fear due to warnings by other DIYers trying to remove the pulley

3) removed alternator and did the job in the workshop. Had to remove the fuel filter assembly to gain access to the alternator.

Removed broken bit in the shaft, used workshop tools instead of Chinese cheapo kit, apart from spline sleeve

Sure enough pulley one way clutch mechanism had failed, picture or video to follow

installed alternator, this is where the fun began! The tensioner requires a 15mm spanner to pull against the spring and enable you to put the belt back on, but the spanner ends up covering the alternator pulley 😞 

I had to remove the top alternator bolt and swing it down, this shortens the travel distance of the belt and allows you to put the belt on the pulley, next problem is to swing the alternator back into position for the top bolt whilst releasing the tension off the tensioner and trying to put the bolt back in. this really puts your thumb muscles into play. The fuel filter assembly is a bit of a ball ache, the bottom separate nut and bolts are recessed into the Citroen aluminium housing.

Would I do the job again? Yes, like many jobs the first time is a learning experience, just take the alternator out, it ends up saving time and frustration 

Darren

Here's a video of how to do the freewheel pulley etc..