Unknown Plug - CEL won't go out.

My '93 Geo Tracker 1.6 L 5 speed with 150,000 miles on it has the
CEL on all the time!

The vehicle works fine, but the CEL is always on. Can this damage
something?

I read "EarlPitts" thread and I have the same problem plus I
have another socket right next to the Diagnostic Socket which
I want to ask about. Hey Earl! Where is the Oxygen Sensor at?

In the Photo Below I connected the Blue-Yel Strp connector hole
to the Black connector hole with a bent paper clip.

Nothing. CEL stays on - no blinking. CEL won't clear when
Battery is disconnected overnight with light switch on....

http://img354.imageshack.us/img354/585/diagpluga7nu.jpg

In addition - there is another socket right next to the Diagnostic
Socket which I cannot identify in the Chilton Manual (p 4-53).

http://img354.imageshack.us/img354/8900/unknownpluga7aw.jpg

Does anyone know what this other socket could be for?

DoctorBill

PS - Where would the ECM for this Vehicle be located?

ecm is behind the left speaker its real easy to get to. I went down and looked at my geo and found nothing that resembles that. Only suggestion I can say is check all your sensors via chiltons and follow the wires back to make sure they are plugged in. Autozone has code scanners.. Maybe they have you you can hook up and pull the code from. Find out exactly what is wrong.

There is also a switch to reset the light. just inside the left front speaker hole. I'm not sure if this will work for you. It seems my Oxygen sensor was shorted, therefore making the light stay on. (its located on the exhaust manifold) Strange how what works on one tracker doesn't on another.
Hope this helps