34 replies to this topic

[MartinS]

Hi all

My daughters car has its battery light on at the moment but it was apparently on and off while driving.

The car starts fine, no error codes are coming up, battery connections are tight and the belt is still on and tight.

The battery is quite new but we will get a multi meter on it and the alternator tomorrow hopefully.

 

How do I get to the alternator connectors in case they're loose?

 

Any other suggestions welcome as were all off to Folembray next week.

 

Martin S

 

[MartinS]

Forgot to say its an NA.

 

Martin S

 

[The Batman]

Thenalternator plug might be loose. Back / bottom of it is where it plugs in. Not sure you can reach without removing intake tho

[haggi961]

New alternator if the battery light is coming on.

[MartinS]

multi meter going on the battery tomorrow (it seems the alternator is 'very' hard to get to). But tonight when dark will fire her up and see if the headlights get brighter when revved. Its crude but it should (shouldnt it?) show the alternator doing something. Am also going to my scangauge to see the voltage though I know that's not the best way.

 

Whats the simplest way of getting to the alternator plug, under or over, or just by feel somehow? (I sense more VX wounds coming on).

 

Martin S

 

[siztenboots]

or just crap wiring corrosion

[MartinS]

scangauge starts showing 11.3 volts with very little change (climbs to 11.7 vOlts)  change after waiting 5 minutes and when the car is revved.

 

fWT rises gradually all the time, i.e started at 105 and was at 175 when I turned the car off.

 

Am I right in thinking 12v is the norm, rising to up to 14.5 when running normally.

 

Martin S

 

[siztenboots]

12.6v is a good battery fuly charged

[The Batman]

alternator sounds nackered

 

if it helps i chucked 3 alternators in the tip today

[MartinS]

Just used a multimeter (which is obviously better than a scangauge) and it went from 11.8 up to nearly 13 but was going up and down with the battery light correspondingly going off and on.

Could that still be a loose connection just jiggling around with engine movement?

 

Martin S

ps And no Joe, that doesn't help, though not sure we'd stick on a second hand one anyway if going to all the trouble of taking one off.

 

ps ps If we end up getting a new one is it the 100 amp. I know that's smaller so would help re fitting. Were unsure hats on it.

[Bargi]

Just used a multimeter (which is obviously better than a scangauge) and it went from 11.8 up to nearly 13 but was going up and down with the battery light correspondingly going off and on.
Could that still be a loose connection just jiggling around with engine movement?
 
Martin S
ps And no Joe, that doesn't help, though not sure we'd stick on a second hand one anyway if going to all the trouble of taking one off.
 
ps ps If we end up getting a new one is it the 100 amp. I know that's smaller so would help re fitting. Were unsure hats on it.

100amp for when you SC it over winter...

[siztenboots]

clamp a jump lead from the --negative-- battery terminal to the engine block , if one of the earths is bad that should sort it

 

[MartinS]

Just to clarify Steve, that jump lead idea would show there's a bad battery earth?

 

Anyone got a picture of how the cables connect to the alternator in case that is loose. Cant find a good clear one anywhere. How is it connected, push on, bolt etc?

 

Martin S

 

 

 

[Lauren(S)]

Bloody car just before track day in France! Got 100amp alternator at the ready

[Exmantaa]

Just to clarify Steve, that jump lead idea would show there's a bad battery earth?

 

Anyone got a picture of how the cables connect to the alternator in case that is loose. Cant find a good clear one anywhere. How is it connected, push on, bolt etc?

 

Martin S

 

 

 

There is a (1 wire) plug that has the battery light connection and 1 thicker 12v wire fixed with an eyelet and nut.

(from my mind this 12v wire is attached to the thick starter 12v supply wire and so directly connected to the battery...)

 

Earth/ground goes through the aluminium engine block and earth strap to the chassis/battery. (check mounting bolts)

 

If the car has no trouble with starting and the alt. wire connections are all connected, probably the alternator brushes worn out. => replace alternator or replace brushes 
 

Edited by Exmantaa, 16 August 2018 - 10:31 AM.

[Lauren(S)]

Ok cool thank you, Havant got time to strip alternator and just replace the brushes so going to replace the alternator and hope for the best!

[leevx2.2]

i have a few 120 amp alternator's in the garage you can have .

[leevx2.2]

sometimes if the car has been sitting moisture corrosion inside the Alternator can cause problems have you driven it to see if it gets better ?

[MartinS]

It happened on the way back from Bedford this week so on a 3 hour drive.

We need to get it done before Friday for the French trip so I am doing what I can but its looking like we will be trying to fit an alternator tomorrow evening (what joy) in the hope that solves it.

Am going to try connectors and earth strap stuff now but not feeling very hopeful. I assume its easier to get it all from underneath?

 

Seems I am still doing VX things on a very regular basis, so glad I got rid of mine so I didn't have to twiddle any more!!!!

 

Martin S

 

[Exmantaa]

NA? From the top and remove right rear wheel arch.

 

The process is probably pictured  numerous times in SC build topics where they had to remove/mount the 100A alternator.

 

Edit; see pics of alternator here in Smileys SC topic:

https://www.speedste...t=4568&start=15