Power Power Power

[Bandooli]

Hi peeps

I normally get all the info and help I need from browsing the forums but this pone has got me.

I have a MK4 1998/9 Golf GTI 1.8t 150bhp AGU and Im trying to figure out this problem with the charging system.

Problem is if I start the car and turn the interior lights on they seem dim until I give the car a good hard rev, then they brighten up. I've had the alternator/tensioner/drive belt changed and replaced the battery about 3 months ago before I changed the alternator.

One time i was driving along and the abs light came on then a few seconds later the airbag light, the dash looked dim so I pulled over and turned the car off for about a minute then tried to start it and it was like the car itself was dead no cranking watsoever and hardly any lights on the dash.

5 minutes later the car started like it just came out of a showroom full of life and bright dash lights.

I was confused

Please please please somebody help its driving me mad.:zx11:

[chris.fulton]

Simple thing to try first would be to clean the battery terminals and leads.

[Nutty]

Simple thing to try first would be to clean the battery terminals and leads.

At both ends of the leads ;)

[Crasher]

You need a new alternator.

[Nutty]

You need a new alternator.


Bandooli said it had been replaced 3 months ago ?

[Crasher]

So he did, still, the symptom is a faulty alternator. I wonder where it came from. A simple voltmeter test can show how the regulator is functioning.

[Nutty]

Yes I agree with the voltmeter and the replacement alty could have become faulty, however I would check the earth lead from the batt to the body as a simple first check, and the security of the leads as they will have been taken off recently.

[pgarner]

i had something similer with my civic. in the end i found one of the earth leads had came loose so would start without a problem sometimes and not another. tightened it up and it was fine for the next 2 years.

[Bandooli]

Kool guys,

I've cleaned the wires and terminals....question as dumb as it may sound.where the heck is the earth from the battery??:Blush2:

P.S I got a mechanic friend to use a voltmetre on the alternator, when the car is started it reads between 11 and 12 but when the car is revved hard it rises to about 14.5 same on the battery:confused:

[Nutty]

Save anyone giving you a wrong lead :biglaugh: Just follow the earth lead from the batt and see where it goes..

The voltmeter reading is correct, if the Alty only pushed out 12V the thing would be in balance with the battery, it has to be higher in order to charge it

[Crasher]

The voltage from the alternator should jump to around 14.2 volts at around 1000 rpm, maybe 1200 rpm at the most. If it doesn’t this suggests a problem with either the alternator or the charge warning light wire. Does the alternator waning light come on when the ignition is on but the engine isn’t running?

[Bandooli]

Cleaned all the wires and terminals positive wire was corroded and needed a good wire brushing, earth is tight and clean also.

One thing I did notice one thing when I took the battery out was a connection on top of the starter motor had a lead not connected so I connected it (anybody know what that connection is for as I must of been driving the car around for ages without it connected lol?)

Thanx alot for the help lets see if things smooth out now;)

TO CRASHER: After cleaning I started the car and the voltage read 14.3 without revving Im gonna check again to make sure the problem is sorted, no warning light, where is the charge warning light wire located?

Cheers