QuestionThanks Josh, I read somewhere that there is a soldered in battery in the instrument cluster and this is usually a source of problems as well for gauges. Cooling system is fine as most of it was replaced 2 years ago and the coolant liquid is clear. Thanks for your quick response!!
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Followup To
Question -
Hi, I have a 1991 BMW 320i cabriolet with automatic transmission. When the car is warm, the coolant gauge is in the 'five to twelve' position and when I'm in heavy traffic in creeps up a little. Now recently, it has begun to stabilise at the twelve position and would go beyond this mark and begin to flicker backward and foreward. Coolant level is fine and and the viscous fan is running when the engine is stationary and at ambient. Is the coolant gauge shot and what would it take to repair this?
THANKS!!! (European car and I live in Belgium...)
Answer -
Dominick,
The coolant and fuel gauges are notorious for having problems. You can pull the cluster, and replace the guage yourself. Pretty simple and strait forward job.
Hope this helps,
Josh
AnswerDominick,
Yes you can (and probably should) replace the batteries on the Service Indicator board (SI board). They often go bad, but I've never seen them affect the fuel/temp guages. Usually it's because of a bad connection with the gauges. The fuel and temp guages have a threaded stud coming out the back, and two smooth posts. The threaded stud acts like a ground, and the smooth posts are the connections to make the guage read higher or lower. If a perfect connection is not made with any of these points, the guage will jump.
So you can change the batteries if you want to, but it will not affect the guages. They need to be unbolted and cleaned/replaced.
Hope this helps,
Josh
