Is my alternator failing

[wilto]

I've noticed over the last couple of weeks that if I get in the car some hours after I've parked up and it was raining when I parked, when starting up the engine obviously the wipers are still in the on position, the wipers sweep across the windscreen really slow for about 5 to 10 seconds. It's still raining by the way. I'm thinking it's either the alternator on the way out or moisture on the drive belt, and it slips slightly until the moisture disappeares.

Anyone else found the same issue as this? engine is 1.8 Duratec. And also I removed my engine undertray about 18 months ago.

TIA Chris

[F0CUE]

When did u last change the battery? Do your lights flash when you start up?

[FatHead1979]

11 hours ago, wilto said:

I've noticed over the last couple of weeks that if I get in the car some hours after I've parked up and it was raining when I parked, when starting up the engine obviously the wipers are still in the on position, the wipers sweep across the windscreen really slow for about 5 to 10 seconds. It's still raining by the way. I'm thinking it's either the alternator on the way out or moisture on the drive belt, and it slips slightly until the moisture disappeares.

Anyone else found the same issue as this? engine is 1.8 Duratec. And also I removed my engine undertray about 18 months ago.

TIA Chris

I ran my 1.8 TDCi for about 6 months without the under tray fitted, the entire engine bay ended up looking minging!

[wilto]

11 hours ago, F0CUE said:

When did u last change the battery? Do your lights flash when you start up?

Never changed the battery, it's been on there since I bought it, do you mean the headlights flashing? don't normally start the car with the headlights on. If you do mean headlights I'll check next time I start the car in the dark.

[F0CUE]

32 minutes ago, wilto said:

Never changed the battery, it's been on there since I bought it, do you mean the headlights flashing? don't normally start the car with the headlights on. If you do mean headlights I'll check next time I start the car in the dark.

When the battery is failing the headlights flash when not on. Not that it will be the battery but could be.

[Tdci-Peter]

15 hours ago, wilto said:

it was raining when I parked, when starting up the engine obviously the wipers are still in the on position, the wipers sweep across the windscreen really slow for about 5 to 10 seconds.

The wipers draw a very small load compared to starting the car. The real test is does it spin over the engine at the usual speed, and start easily.

It is just possible one cell is going on the battery, but I think this would still be more noticeable when starting.

Best test is to measure the battery volts with a voltmeter. The complication with that is the voltage always depends on what happened in the last hour or so. But after sitting overnight, it should still be 12.3v to 12.6v (12.6 ideally, but just unlocking will knock it down a little. And then rise to over 14v after the engine has been running for a minute or two. >14v should be then maintained even with headlights & heater fan on.

If the battery is ok, and being charged at >14v, then one suspect is the wiper parking switch mechanism inside the wiper unit. This is only used when the wiper switch is off, and they are parking. It can become a poor contact. Then I would suspect the rest of the wiper mechanism, getting stiff or inefficient. It may work ok at 14v (engine on), but not so well at 12v (engine off). Other suspects are wiring and earth connections.

[Dee_82]

having had to change my alternator the other month, I can tell you that slow wipers are absolutely a potential sign of a lack of available current. Once the car is going the battery doesn't do much at all. so if you get the car ok then its less likely to be an issue, you would expect the voltage to be in the 14 range whilst running, with nothing on. turn on the lights, fan, wipers, the whole works and see what happens, you would expect there to be a small drop in volts but stay above 12v ideally it should hold at 14  the current is the most important one you cant measure though. when the alternator starts to fail it stops being able to generate high current, it might be fine on volts but if underload the current is low then you can expect to see dimming lights, slow wipers warning lights, the whole works. 

I literally picked up an alternator got almost home when it totally died, hazards and everything on the motorway on a bridge, no place to stop. I managed to free wheel down a hill to the hard shoulder, I knew it was dodgy, I knew the wipers were going slow, then without warning, I got warning lights all over and about 5 seconds later she died. 

 

[nazsky786]

Simple dash cluster test will show the battery power before start up and once started. It should be 13-14 volts when charging and 9-12volts when engine off. 

To test a battery correctly you need a load tester. Alternator you need multimeter, but dash test is free test. And will show you any issues. 

[nazsky786]

O and Ford use a smart charging system so numbers with fluctuate 

[wilto]

Just been pricing up some alternators, ranging from £120 referbished to a whopping £290 for a new one from Ford's,

I will see how it goes in the next couple of weeks, at the moment it spins the engine brilliantly and fires up straight away, no issues with alternator light, im tending to lean towards the engine bay/ drive belt being damp and slipping ever so slightly on start up.

As I said earlier it only seems to happen when I've driven either to or from work in the rain, parked up, got back in 12 hours later, started engine and wipers still on, wipers wipe across the screen for the first three or four sweeps quite slow, give it a quick blip on the throttle, and they go back to normal speed.

[Dee_82]

The important point here is that battery can fire her up, so even if it is a gonna, its doing a good enough job. the alternator is providing enough of a current to top her up. but the alternator doesn't do its job straight off the bat, it has a clutch system that only kicks in fully when you accelerate, so it could be partly the battery, but topping up a battery is not a big job for the alternator so it might do that fine, that's what happened to mind, battery fine, but it struggled with additional load until it gave up.

but again, its worth keeping an eye on this alternator because if it goes, you may not have any warning at all or at best, you might get some ABS TC lighting up on the cluster when the battery is about to give up. I discovered a good way to tell if the alternator isn't doing it job is start the car,  turn on the overhead lights, thenturn on your headlamps and see if the overhead lamps dip, then turn on the wipers and check again, flick back and forth so get a better idea. if it dips, and that's only a 5w load to that bulb, the alternator is struggling. 

 

[Tdci-Peter]

6 hours ago, wilto said:

started engine and wipers still on, wipers wipe across the screen for the first three or four sweeps quite slow, give it a quick blip on the throttle, and they go back to normal speed.

It is absolutely normal for the system to stay at about 12v for a little while after starting. I have just the same, voltage stays down until revs rise a bit. Also on a cold start after standing a while, it may take a bit longer for the system voltage to stabilise. I can hear the heater fan changing speed as the voltage goes up and down but I also have an in-car voltage display.

Cigar lighter voltmeters are cheap, and useful if in any doubt about the system voltage. They are a bit inaccurate, partly because they are cheap, but also the voltage at the power point will differ from battery voltage by a bit, depending on loads drawn by various equipment. So if you get one, compare with the actual battery voltage at a couple of conditions (eg before start, and under normal driving load) to see how it lines up.

The Ford smart charge, so called, is a potential confusion, but it has been around for many years (1990s, I think), and the 12.6v (idle) and 14.4v (full charge) battery voltages are still the same. They certainly are on my 2006 car. The Mk3 Econetic start/stop system is more complex, and may aim to maintain only 80% charge on the battery, a very dodgy and user unfriendly idea in my view! It will have a more complex voltage pattern.

All lead-acid (that includes calcium, AGM, EFB and SLA) batteries have similar voltages, give or take about 0.2v: 14.4v to get up to maximum charge, 13.6v to maintain full charge, 12.6 no load or charge in good condition, are typical.

I have had 3 alternator failures, two were with no warning or previous symptoms, just the battery light came on, and I could tell it was not charging. I managed a 35mile trip back home on the last failure (daylight, and keeping load to a minimum), the battery was flat enough to set fire to my old charger when I got home! But it made it.

One failure the car just lost power and came to a halt. I do not recall the alternator light coming on, but that one was about 28 years ago (in a 2l Sierra)!

Testing car charging systems just by voltage is not dead easy, but possible with a bit of work. To test an alternator, as the others say, you need a heavy load. Heated screens are about the biggest normal load, then main beam headlights. Heater fan on max is a surprisingly heavy load too. After a run, when the battery should be charged, leave the engine on idle, turn that lot on, and then see how many extra rpm it needs to keep the voltage up above 13v (at the battery). Even at idle, it should just about cope without pulling the battery down much below 12v.