temp guage

[grattsim]

I have a 96 1.8 Laguna RT. I've had too many problems to list, my current one seems to be electrical. My temp guage increases with engine speed. Its had a flush and new water pump and rad before plus I've most of the earth points have been checked. Any help would be good. Before changing the main gearbox earth strap when the rear heater control was switched on the guage also went up. Any ideas?