wont start

[r10crw]

Ross, measure the batt voltage when starting the engine from cold and determine if the alternator is genuinely not working from cold. If you getting around 14-15 volts then I would guess that the problem is most likely an earthing issue, maybe through the temp sender to the engine. Try the old jump leads.
Cheers Craig.

[r055]

Ross, measure the batt voltage when starting the engine from cold and determine if the alternator is genuinely not working from cold. If you getting around 14-15 volts then I would guess that the problem is most likely an earthing issue, maybe through the temp sender to the engine. Try the old jump leads.
Cheers Craig.

Thanks Craig - I measured the voltage a few weeks ago just before the light went off.
My calibration was out on the meter so didtn get the exact voltage, but was able to see a jump between the light being off and on. You can hear a difference in the engine tone as well once the light goes off.

[r10crw]

Not so sure then Ross, sorry mate. However could still be an earthing issue with the engine, the alternator needs an excitation voltage before it will start to charge and its possible it does not see this until a return path is available through the temp sensor? Longshot but Id still try running jump leads front to back, it always seemed to sort all strange issues with N1.

[r055]

thanks

[tut]

Going to try that with N3 Craig as I am still getting these turning over problems, and the headlights come on when trying to start.

tut

[Lewis]

No, it's the opposite - the fact that the car started again once the bat was recharged, then ran around the block with the bat warning light on means (to me, anyway) that the alternator is not putting out a charge - either the belt has gone (not common), the alternator has seized (happens, or at least people say it happens) or the regulator pack is bust (happens) or the wiring loom or maxi fuse is bust (happens when people do bad things with jump leads).

Cheers,
Robin

It was the alternator
car running well but alarm is playing up now

[ClarkyBoy]

Going to try that with N3 Craig as I am still getting these turning over problems, and the headlights come on when trying to start.

tut

my elise did that if the battery was too dead to start the car, when you let your key off the ignition, all the lights came on.....it was an odd one, but only did it when the battery was dying??

[Stewart]

Thread resurrection

Since buying may S2 111S at the end of November, it has seen very little use. As such the battery seemed to be very dull and would only throw the starter over very slowly if left for more than a week. After leaving it for the whole of December it was completely flat so I took it out and charged it up. That seemed to do the trick. I then gave it a quick run every couple of weeks since. The battery still seemed quite dull, but better after getting back from a run.

I went to it to today and the starter seemed to turn over the engine as I would expect a fully charge battery to do (for the first time since getting the car). It is probably the mildest day since I bought the car that I have driven it. I then went out for a run. As the roof was off the blower was on full speed, the headlights (HIDs) were on for the whole journey as was the radio. After 30-40mins of driving the battery light flicked on and stayed lit. Turning off the electrics while driving didn't make any difference.

As I neared home - 10 mins later - The radio cut out but headlights were still on. I reversed into the drive and left the car running while I opened the garage door and then reversed it in and switched it off. I immediately tried to restart it but it was almost dead. It wouldn't turn over the engine but I did have the dash warning lights illuminated.

I am thinking battery as the alternator appears to have worked enough to re-charge the cattery during each previous wee run since January. Or is it more likely to be the alternator?

Should I take the battery out and re-charge it and see if it takes a charge? My father has some kind of battery checking meter, but I am not sure what I should be looking for and am not confident he does either I am guessing that the meter will need a charged battery and a running car before it can tell me anything?

All advice greatly appreciated.

Thanks

Stewart

[tut]

Bit apprehensive about giving advice Stewart as I seemed to have fcuked up the last three lots, but I will try with the basics as there does not seem to be an expert around at the moment. If the alternator is not charging you should have a permanent red warning light on, and a fully charged battery will last less than 1.5 hours with no lights etc draining it before it drops below 10 volts, at which stage the ECU will cut out.

You can check the battery with a voltmeter with it in the car, engine off, a healthy battery will read 12.5-13 volts. Start up and check again, if the alternator is functioning OK it will rise by around a volt.

tut

[Rich H]

What he said.

If the alt was not charging then you would get a red battery light - if everything works!
Does the battery light come on when you turn on the ignition then go out after it starts?

The battery might just be knackered, they will appear to charge but won't have any capacity.

Rich

[Stewart]

Thanks guys.

What he said.

If the alt was not charging then you would get a red battery light - if everything works!
Does the battery light come on when you turn on the ignition then go out after it starts?

The battery might just be knackered, they will appear to charge but won't have any capacity.

Rich

It just happened this afternoon. The car wouldn't start after I switched it off - there was very little life left in the battery.

I might get time to stick a meter on it tomorrow. I am really leaning towards the battery but I think you are both saying that the symptoms are the alternator.

[Rich H]

If the battery light comes on then goes off and it's giving 13.8V when running then it's not likely to be the alt.

[BiggestNizzy]

My money would be on the battery. Put a meter on the battery and check though and full it out but if the alternator wasn't charging you would expect the light on in the dash

[tut]

I am assuming that you do not have a voltmeter Stewart, as you could determine if it is the alternator straight away, or the battery itself.

If you do not have one of our mob nearby to help you out, drive into QwikFit or similar and get them to check it out. Do not let them fit any new parts at this stage, but they will do a free check.

tut

[CubanGav]

I had a similar problem. The battery light came on while driving but went off when I raised the revs. As headed home the electrics died one by one. Stopped at the side of the road it wouldn't start and the alarm was going wild every time I turned the key. Alternator bearing was goosed. Got another fully charged battery to get me home. A multimeter across the battery showed no increase from 12v with the engine running. Turns out that it had sat too long with no use (for reasons I can't disclose) and the already iffy alternator bearing had gone. Reason I mention it is that the battery light was on and off for a bit before it went. A cheapo halfords multimeter would be the best move.
I can't claim to know anything and can only pass on advice that was given to me.