Khranok

Khranok

Active Member
My battery warning light stays on when I turn the ignition. Giving it a few revs makes it turn to a dimly lit state. The headlights won't come on properly either, they just flicker. They are a HID kit though and have always required a few revs to get them to come on to full brightness once turning them on. The alternator seems to all be wired up properly and there are no other electrical problems so I can see, spot lamps work fine, central locking etc. Checked all the fuses too.

Any suggestions? Dieing alternator?
 
Check the voltage you are getting at the battery using a multimeter set to volts you should be getting 13v+ at idle ;)
But if the warning light is on/dim with the engine running it looks like your alternator is on its way out !
 
DEFENDER90-DAZ said:
Check the voltage you are getting at the battery using a multimeter set to volts you should be getting 13v+ at idle ;)
But if the warning light is on/dim with the engine running it looks like your alternator is on its way out !
Click to expand...

I think the battery has been having a slight drain for a while too. Could that also be the alternator perhaps?
 
Yes, your battery isnt being re-charged after starting. Once the alternator kicks in your battery isn't used. It will not last long if you're using battery power for lights etc.
 
storm99 said:
Yes, your battery isnt being re-charged after starting. Once the alternator kicks in your battery isn't used. It will not last long if you're using battery power for lights etc.
Click to expand...

It does give it some charge, maybe not enough though. On fairly long journeys my headlights have always stayed on, although lately they have been struggling to come on a little more than normal but once they are on they do stay on. I understand them ballasts need a significant charge to come on however.
 
Read that a shorted diode in the alternator can cause a parasitic drain when the engine is off?
 
Khranok said:
Read that a shorted diode in the alternator can cause a parasitic drain when the engine is off?
Click to expand...

Hmm...interesting theory, sounds theoretically plausible dependant on the perceived collatoral impact viability.































Could be bollox though.
 
Haha, guess I will have to borrow a multimeter from the parents and check it tomorrow or Friday :)
 
Right booked it into Halfords for a battery and alternator test on Saturday. Think I may buy the 100amp alternator while i'm at it if this one is shot. The engine always dips a little when I put my spot lamps on as well as the HID headlights, plus I wanna put a subwoofer and amp in the back soon too :)
 
Also I have a 200tdi disco engine in mine, do I take the old alternator out and remove the front pulley

68j2fCr.jpg


and remove and replace this one with the old one

qPWD9H2.jpg


As they obviously use different types of belts?
 
Yeah as thought it was the alternator not giving a charge. So if I order the 100amp one its just a case of taking off the old one, taking off the 200tdi style pulling spool and replacing the newer 'serpentine' style one on the 100amp alternator with that?

Then just slap the new one on and good to go right?
 
I'd use heavier cable from the alternator to the common live on the starter motor to cope with the possible 100amp output of the alternator ;)
 
Fitting my alternator tomorrow, the wiring I currently have looks similar to this...
qOfWpL0.jpg

With the two thicker brown ones connected to the same point. It also has a green wire attached to there that goes somewhere down by the headlights, I dunno what that is, I will just slap it back on where I found it.

Will I need to upgrade these two wires to a higher gauge before fitting the 100amp alternator? These ones were connected to the 65amp prior. If so where can I find them (Halfords?) and what gauge should I get?

Thanks :)
 
Would deffo upgrade the brown wires back to the starter - might just be the piccy, but looks like one of your brown wires might have an insulation crack anyway (one with the yellow ring connector), so well worth swapping out

Halfrauds should sell or any decent motor factors - there are charts for the cble gauge, but they are usually current rated anyway - just look for 100 amps + :D


EDIT: Had a quick google for you - 2 gauge should do but personally I'd over spec and go 1/0
 
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