RangeRovers.net Forum banner

1 - 3 of 3 Posts

·
Registered
Joined
·
3 Posts
Hi everyone, I have a 2008 HSE 4.2 supercharged. My battery light came on. So I did a check on my battery. Battery was good I check to c if alternator was putting out voltage and it was not. So I removed the alternator had it tested and came back good. So I proceeded to check my 3 wire plug that goes into the back of the alternator. Everything looks fine but when I check the voltage on each wire individually 1 has a 12 volt current second one has a fluctuating current between 5- and 6 volts and the 3rd wire is dead no current at all. So I took a chance and tapped this wire with a 6v current and my alternator came to life and my battery light went out. I have tried to track this wire down to c if there is any type of in line fuse or something I'm not seeing. I've checked all fuses under hood in glove box and in hatch area. Nothing else in the vehicle seems to b malfunctioning just this one wire is not send current to the alt to turn it on and off. Can any one help any me please. Any ideas can help. Thank u in advance

3 wire plug to the back of alternator

1 wire that gets a 12v feed is brown w/ green strip
2 wire that gets 5-6v current is white w/ green strip
3 wire that gets no current is white w/ red strip
 

·
Registered
2006-2009 Range Rover MkIII / L322
Joined
·
1,190 Posts
Your white with red stripe is the alternator control voltage, its what regulates the amount of charge going to the battery based on the voltage being sensed on the green with white wire. Both of these wires go to the ECM. The brown with green stripe is the battery sense that comes thru the ignition switch and a 5A Fuse, 2E in the fuse block in the glove box. The voltage on the white with red striped wire comes from a relay contact the ECM itself.

Starting and Charging diagram VIN 198058 onward.jpg
 

·
Administrator
Joined
·
27,818 Posts
https://www.rangerovers.net/forum/6-...eshooting.html


Here are the generic basics follow through the tests with a basic multimeter. These are tried and true measurements to check your battery, alternator AND cables for resistance if you have cruddy cable ends at either end or a cable failing it will have high resistance and no amount of prayers are going to get perfectly good alternator to charge a battery.
 
1 - 3 of 3 Posts
Top