Got a problem with my VS.

[Dyson]

Hi guys, i have a problem with my VS. Whenever i have the lights on it will idle at about 1500, and when i turn the lights off it will drop to around 900 like normal. It's really awkward to drive with the lights on when it's idling high like this.

Anyone know what is causing this?

Cheers.

 

[mint]

I would say your battery is cactus.

 

[Dyson]

I've just bought a new battery 2 days ago. This problem was there before i put the new battery in too.

 

[carcollector]

Check your chassis and engine earths. If any earths are buggered or loose, when the electrical load on the alternator increases, it increases its output to compensate. If for example the engine to chassis earth is stuffed, it will interfere with all of the sensor readings from the engine, and this can cause problems. The reason is that the engine earth may be different to the chassis or battery earth, and a sensor reading, for example a temperature sensor reading may be reading 7 volts instead of 9 volts. The ECU then gets confused. Easiest way to check is to have the car idling with the lights on, and use a jumper lead attached to the battery negative. Attach the other end to the engine, and if the revs drop, you have an engine earth problem. Attach it to the chassis, and if the revs drop, you have a chassis earth problem.

Hope this helps.

 

[Dyson]

cheers for that. i'll gave that a shot tomorrow. : )

 

[Dyson]

just tested it. the revs go down when i attach the lead the chassis, so i guess it's a chassis earth. thanks for that mate!