I'd like to thank everyone for your help. The old circuit board looked like it was losing it protective coating. The new circuit board has a protective rubber coating over the board and only the resistors were exposed. I bought a ACDelco part from the local Chevy dealer. GM 89018643 on the box and
89019101 on the invoice. Listed for 53.77, Charged 40.58. Works like charm! Thanks again, Mark