Pulling codes

1993 merc GM 4.6 auto 90,000 miles. Check engine light comes on for a few minutes then will go off and come back on. Is there a way to check codes by key on/ off or any other way.without code tool. Its an obd1 so the local auto parts can't check it I do not want to spend $65.00 min to have the code read. Thanks

http://www.ebay.com/ Search 300317302048
You can use a DVOM analog type and count sweeps but their is a 1/2 pulse and if your not aware of it will get the wrong code. This one is under $20.00
Some parts stores sell them.

Click here (http://www.troublecodes.net/Ford/) It gives instructions and the code meanings bolow.