Hi All,

FYI before I go into my story this is an 11 plate 1.6 Ecoboost petrol engine with start-stop.

having lots of issues with my S-MAX of late, first of all it was suspected a power drain whilst the car was stood still but now seems like an issue with the alternator.

The power issues first started after driving around all evening and when waiting at the last stop for my Son to come out of club the car warned me low battery.

Days later I got stuck at traffic lights with no ability to turn the engine over, RAC tried to jump with nothing happening.

Mechanic pronounced the battery dead at the scene and put a new, larger battery (have no idea if its the right type). Anyway all fine for a few days but the starter seems to be getting slower and even whilst driving home last night the power steering failed, battery light came on etc... The car would not start at this point.

Now this morning car would start and I found the in car diagnositcs (thanks you tube), now the battery on the dash display (I don't have a volt meter handy), reads 12.6V even when the engine it running, then put stuff on like lights heaters this goes down to under 12 volts. If this is showing power at the battery terminals I assume this would be higher as the alternator charges the batter, but hay I don't know.

Anyway looking around the web there seems to cables going into the alternator, the power output and regulator connector. Now these videos ect talk about a 3 pin connector, but looking under my bonnet (looks like the alternator is on the front left of the engine, there are 2 connectors a large cable (power to battery) and nother connector, but the connector has holes for 2 cables and only 1 cable going in ?!?!?

I was looking to unplug second cable to turn the alternator into none smart mode and see if that charged the battery.

Anyone have details on this engine and its alternator, also the second plug, should that just pull out or is it clipped in?

Thanks to any help recieved.

PS have attached image of what I think to be the alternator and its two connectors.

Hi All,

FYI before I go into my story this is an 11 plate 1.6 Ecoboost petrol engine with start-stop.

having lots of issues with my S-MAX of late, first of all it was suspected a power drain whilst the car was stood still but now seems like an issue with the alternator.

The power issues first started after driving around all evening and when waiting at the last stop for my Son to come out of club the car warned me low battery.

Days later I got stuck at traffic lights with no ability to turn the engine over, RAC tried to jump with nothing happening.

Mechanic pronounced the battery dead at the scene and put a new, larger battery (have no idea if its the right type). Anyway all fine for a few days but the starter seems to be getting slower and even whilst driving home last night the power steering failed, battery light came on etc... The car would not start at this point.

Now this morning car would start and I found the in car diagnositcs (thanks you tube), now the battery on the dash display (I don't have a volt meter handy), reads 12.6V even when the engine it running, then put stuff on like lights heaters this goes down to under 12 volts. If this is showing power at the battery terminals I assume this would be higher as the alternator charges the batter, but hay I don't know.

Anyway looking around the web there seems to cables going into the alternator, the power output and regulator connector. Now these videos ect talk about a 3 pin connector, but looking under my bonnet (looks like the alternator is on the front left of the engine, there are 2 connectors a large cable (power to battery) and nother connector, but the connector has holes for 2 cables and only 1 cable going in ?!?!?

I was looking to unplug second cable to turn the alternator into none smart mode and see if that charged the battery.

Anyone have details on this engine and its alternator, also the second plug, should that just pull out or is it clipped in?

Thanks to any help recieved.

PS have attached image of what I think to be the alternator and its two connectors.

I've only just joined the forum today and haven't got my SMax yet but thought I'd contribute even though you've probably got it sorted by now.

I'm no expert but it does sound like an alternator fault to me. Generally even a flat battery will show 12v if there is no current being drawn from it. If the battery is dead you will notice the 12v fall away to low levels when the battery has to deliver current to any operated device, while a good battery will maintain 12v for a good period of time.

You can check your altinator by starting the engine and putting your head lights and heater on. Rev up the engine and you should see the brightness of the headlights go up, indicating an increased output from the altinator. If nothing is noticeable chances are that the altinator is duff. If you have a voltmeter you can also connect it across the battery terminals and it should read around 12v, revving the engine should increase this to just over 13v, this also indicates that the alternator is good.

All modern cars draw current from the battery when they are switched off and standing because of the various computers etc on them remaining powered up when standing. Your alarm system also draws power when the car is standing, my 350Z draws around 0.7A just standing with the alarm activated, so if my battery is a fully charged 50A per Hour then it will take 50/0.7 hrs to fully discharge it.

Hope this ramble helps in some way

Thanks, I found the diagnostics menu in the car and with the engine running the battery voltage didn't change so there was no charge coming from the alternator. Got the RAC out a second time and found there was a massive draw which was caused by a lack of earth on the engine.

Discovered the earth cable was not bolted down, so the alternator was not charging the battery. With that screwed down and running the car the diagnostics view you can see the battery voltage jump up to 15 volts.

Its all working AOK now, just worried what else the last mechanic didn't bolt down :-S