Nissan 1999 GU ST computer problems

Dwayne,
I'm not sure if this will help or if it's a similar fault, but I have seen a case where the GU owners fuel guage was going to empty when he hit the spot lights. This was caused by the fact that his spotties were earthed at the bullbar at their mouning points, and obviously the bullbar is mounted to the chassis. The problem was that the chassis wasn't earthed to the body, because of the rubber mounts, and the battery earth went to the motor and body. Iv'e also seen this problem with trailer lighting because the towbar is mounted to the chassis.
Whats happening is your fuel tank sender wiring is providing an earth path back to the dash, because the fuel tanks sender is the only electrical component mounted to the chassis.
In this case it was fixed by simply fitting a 16mm cable from the body to the chassis, so the first thing I would check is if there is any resistance between the body and chassis, and if there is, fit the wire.
Hope this helps.
Chaz

Earth problem, not computer....
Most likelly chassis to body earth...

Dwayne

I mate of mine with a 2000 GU had a similar problem. Nissan first fitted the earth strap at a cost of $100. This did not solve the problem. It turned out the voltage regulator in this alternator was shot and so it was not charging his battery, this in turn was causing his computer to mal function.

Angus