1988 740 GLE Start up problems
 

I have a 1988 740 GLE wagon that has some strange things happening to it on start up. The gauges will not read properly untill the temp. gauge reaches half way. The tach, speedo, and gas gauge do not read correctly. And the overdrive light and the battery light are on until the temp gauge reaches half way. Once the temp gauge is half way, the lights go out and all gauges work normally. this problem is not constant and does not affect the running of the car. the one thing that seems to affect the above problems is the out side temp. The previous owner stated that it will not start when it is above 90 degrees outside, we have not had the car long enough to experience this as of yet.
Other than that, I love this car.
Any ideas?