Battery drain, alternator or both

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Zakarius
Posts: 8
Joined: Mon Apr 18, 2016 8:19 pm
Currently Drives:: Vauxhall Corsa VxR 2016
Renault Megane 1.5 2003

Battery drain, alternator or both

Postby Zakarius » Wed Apr 27, 2016 2:00 pm

Hi, so got my 53 plate 1.5 dCi megane which I'm slowly repairing (Steering rack was just a pinch bolt, thought it was axial joint), got it through its mot for £200 and now my next problem is if I leave it for 12 hours overnight, the car will not start or it will but really struggle.

So I charged my battery overnight in my house, put it back on the car and it started pretty much instantly. I tested both the off voltage which was 12.5v and when running is at 12.6 volts, even with everything swtiched on. The unit is a 14v alternator so I'm assuming this is the problem.

Would it also be reasonable to suggest a battery drain, even if only charging at 12.6v

I have only tested each of the wires using my clamp on meter and got the smallest reading it will measure of 0.1A, however it reads this sometimes anyway. I've not tested in series yet with my other meter.

So alternators are expensive that I've found online, around £120 from ECP, I can get one from ebay for £35 but will this do the job for a year or so? I'll be fitting my self if possible

I've also read about a diode which may be leaking, where is this located so that I can test it?

Thanks, Zak

Zakarius
Posts: 8
Joined: Mon Apr 18, 2016 8:19 pm
Currently Drives:: Vauxhall Corsa VxR 2016
Renault Megane 1.5 2003

Re: Battery drain, alternator or both

Postby Zakarius » Wed Apr 27, 2016 2:09 pm

Also if buying a cheap on from ebay, which numbers should I be looking for when buying one, I have the following details from the one on my car. I want it to be a straight swap

Valeo
403011420

14V TG11C011 2542664B
8200 100907
50/110A

Danny87
Posts: 3
Joined: Tue May 29, 2012 6:41 pm
Currently Drives:: Megane II

Re: Battery drain, alternator or both

Postby Danny87 » Wed Apr 27, 2016 3:16 pm

With the engine and alternator running the charging voltage should be somewhere around 13.5 and 14 volts. If it is lower I think there is a problem with your altenator.

Charleekap
Posts: 8
Joined: Wed Apr 27, 2016 9:28 pm
Currently Drives:: PH1 Megane (2004)1.9 dci Dymanique

Re: Battery drain, alternator or both

Postby Charleekap » Wed Apr 27, 2016 9:52 pm

I had a similar problem with 1.9dci a few months back. The problem was with the battery discharging. I put a new battery in and not had a problem since.

Might be worth considering

Zakarius
Posts: 8
Joined: Mon Apr 18, 2016 8:19 pm
Currently Drives:: Vauxhall Corsa VxR 2016
Renault Megane 1.5 2003

Re: Battery drain, alternator or both

Postby Zakarius » Thu Apr 28, 2016 3:16 am

I will charge up the battery when I get home from night shift and leave it out the car and monitor the voltage over a day or so. I have paperwork to suggest the battery has been changed in December 15.

I don't know if there are any alternator experts here, but I've been chatting at work, I've found a refurb kit for just £7 delivered. An experienced electrician thinks it could be the windings though and is telling me not to bother changing the bearings etc.

For £7 I think it's worth a shot, the car is just a secondary so not needed urgently.

Zakarius
Posts: 8
Joined: Mon Apr 18, 2016 8:19 pm
Currently Drives:: Vauxhall Corsa VxR 2016
Renault Megane 1.5 2003

Re: Battery drain, alternator or both

Postby Zakarius » Thu Apr 28, 2016 5:28 am

So we've already got the bearings and brushes in works store so I'm going to replace them tonight, hopefully that is the problem and back on the megane tomorrow, will update soon. Following a guide I found on here

Zakarius
Posts: 8
Joined: Mon Apr 18, 2016 8:19 pm
Currently Drives:: Vauxhall Corsa VxR 2016
Renault Megane 1.5 2003

Re: Battery drain, alternator or both

Postby Zakarius » Thu Apr 28, 2016 2:10 pm

Just to update

Im having problems removing the alternator. I've removed the belt and top bolt, loosened the bottom bolt, can't remove completely yet, but the alternator will not budge whatsoever. Tried gripping it and yanking underneath but no nothing, tried hitting from above downwards, nothing still. If all else fails will find a bigger hammer tonight.

If the bottom bolt is completely loose should I have some movement?

Zakarius
Posts: 8
Joined: Mon Apr 18, 2016 8:19 pm
Currently Drives:: Vauxhall Corsa VxR 2016
Renault Megane 1.5 2003

Re: Battery drain, alternator or both

Postby Zakarius » Thu May 05, 2016 8:08 am

Update after completion.

Top bolt was removed but couldn't move alternator, got some penetration spray and a crow bar. When the alternator is tilted as far as it can go, you can get your 13mm on the bottom bolt to remove it. Filed edges once removed and replaced brushes.

Fitted back in fairly easily, recorded 13.4v (with lights on) at idle, as opposed to 12.5 before changing the brushes. Still a bit low but at least it's working now. Noticed the belt had some splits on it, so will replace when I get a replacement


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