I am doing some diagnostics on an '85 190E that won't start. I want to first make sure I have spark, but the repair manual I have says to never crank the engine with the spark plug out of the engine. I have read posts that say to check for spark this way. What is everyones take on this? Can I check the coil by putting a spark plug on the wire that normally goes to the distributor cap?

Thanks
Dan