I thought all the E36's (at least the 6cyl ones) would have at least the basic check control panel located just below the stereo infront of the gear lever.
If you have that check control panel, push the 'check' button and the display should state what the problem is. If you haven't, got a check control display panel then I would start off by checking that all of your lights work, coolant level isn't low and as mentioned low washer fluid level.