VW TDI forum, Audi, Porsche, and Chevy Cruze Diesel forum banner

1 - 9 of 9 Posts

·
Premium Member
Joined
·
107 Posts
Discussion Starter #1
Wow, this car has been giving me some issues, found a loose hose but now there's a low battery light on the dashboard. I assume this means that my battery is bad? Or my alternator? How can I check it?
 
D

·
Guest
Joined
·
0 Posts
It could be a number of things. First check the battery and alternator charging.

To do this, take a voltmeter and put the pos-pos neg-neg probes to the batteyr. it should be in the 12V's when the car is off, 14volts , about, when the engine is running.

The problem might also be in the voltage regulator on the alterator, a loost ground, or a bad battery too.

Or you could take it to autozone and have them run a test , it's free.
 

·
Premium Member
Joined
·
107 Posts
Discussion Starter #3
Well, measured it with a multimeter and had someone rev the engine.

A solid 12 V engine at idle, and engine revved up...battery light still on.
 
D

·
Guest
Joined
·
0 Posts
take the car to autozone...and put a pair of jumper cables in the trunk just in case...and leave the headlights and radio off.

more than 12V should keep you moving, 13V would be better, any less and it your car might lose electrical power.

You can also remove the alternator and battery and take it to autozone and have them test it. Did you check that the battery terminals were tight and clean? That can cause problems as well, good luck
 

·
Super Moderator
Joined
·
23,902 Posts
This happened to me not too long ago, on mine, the alternator was just old.

The book calls for 5mm on the brushes attached to the voltage regulator. Mine were bad, and a new one costs about $90, special order. A rebuilt alternator costs $110 with a core charge, so I just got that since the alt had other worn parts.
 
D

·
Guest
Joined
·
0 Posts
At least there's a light on the dashboard. If that light burn out, the alternator will stop charging the battery in the mk3 cars. Kind of stupid, but something to think about.
 
D

·
Guest
Joined
·
0 Posts
I am sure. The alternator has to get some "starter" electricity from the dashboard warning light and then sends it to the battery. It's in the service manual too.
 
1 - 9 of 9 Posts
Top