Help! Mk2 Battery/alternator Problem

March 10, 2008

Hi Guys,

Everything has been perfect with my GS300 until this weekend, decided not to start on saturday, immediately jump started it, ran perfectly, Battery tester showed that even after a 50 mile drive on the dual carriageway the Battery was only half charged, and then failed to start on sunday morning. I have put a brand new Battery in from Halfords, and on starting the car it started to make a terrible grating/squeaking noise which seemed to get louder as the revs increased, but the car still drove fine and performed as usual despite the noise. Fast forward to today and the car refused to start this morning so it seems to me that the alternator is not charging the Battery, although the noise has now gone.

Does anyone have any suggestions, and if a new alternator is required how much can I expect to fork out?

Many Thanks.

Einstein · March 10, 2008

It's easy to test the alternator... connect a multimeter to the Battery, and measure volts... normally around 13V for a fully charged Battery..

Start the engine, and the volts should rise to around 14.4V (normal charging voltage) much less, and your alternator could be done for...

Check the condition of the drive belt though.. sound like it may have been slipping...

John

RayKhan · March 11, 2008

there is currently someone stripping a MK11 on e-bay so you maybe able to get the alternator from them.

March 11, 2008

Hi Guys,

have tested voltage across Battery terminals with engine running at idle, and I was seeing 13.99 volts, does this mean the alternator has had it?

Many Thanks.

Einstein · March 11, 2008

A fully charged Battery has 6 cells of 2.2V each, giving 13.2V maximum... meaning that the alternator is charging very slightly.. it should be around 14.4 at idle, but can be a tad lower.. and slightly higher when revved..

does it go up a bit more if you rev it a bit, (say 1500rpm) ? it should..

If no, then it looks like it is on it's way out... and as it is low at idle speed, my guess is it needs replacing...

John

March 13, 2008

update - sourced an alternator from a low mileage gs300 off eBay for a good price, and have purchased a new alternator belt, how many hours labour do you think it is to get these parts fitted?

Cheers.