I know that there are a million threads that discuss the homemade code reader (LED/Switch version).

I have spent hours trying to figure out how it all works... And my head is spinning. I'm far short of being able to call myself a decent DIY mechanic, and so most of the discussion on these boards is acronym-heavy and goes over my head.

Can somebody just put in in super basic terms so that other noobs like me searching around can figure it out? I know how to build the tool and have the part numbers, that's not the problem.

1. I need to know where my 16-pin diagnostic unit is on my 1990 300ce-24v and where to plug stuff in (I've heard plug the read banana plug into pin #1 and the black (ground) into #3, but I dont' know if that applies to the 16 pin version)

2. I need to understand what the switch does and how you use it (when do you push it, for how long, etc)

3. How do you read a code? For example, if I plug the 3rd banana plug into one of the 16 pins, do what I need to do with the switch, and how do I know what the code is? Does it depend on how many times it blinks, or is the code dependent on which pin makes it blink at all?

4. Lastly, I've seen lots of different versions/tables on how to interpret the codes. Where is the best source of information for my car? I would hate to use the wrong version of info and replace something I don't need.

I know, I sound like an idiot. But I have spent a fortune at the mechanic trying to figure out a rough idle/hesitation problem... my choice is either to get rid of my car due to heavy maintenance costs, or start turning a wrench myself a bit. So if you can please help out a noob, I'd really appreciate it.

And if I could make a recommendation to the forum, I think it would be an incredible service if Arthur Dalton or someone else very familiar with this subject wrote a DIY article. That would help so many people.

Thanks!!

Peter