The circuit board does not usually need replacing but rather a bit of extra soldering. The circuit board is directly under the cover of the wiper motor and gearbox assembly on the firewall above the brake booster. Usually the solder cracks right where the connector pins are attached.
1995 GMC 2500LD,6.5L TD,Ext cab, SB,4L80E,3.73,Heath Chip, Turbomaster,Hayden fan clutch, 3\" exhaust,K&N filter,Aux Fuel tank, High Idle,Remote Start,Homemade headlight booster,2 inch suspension lift,285/75r16 wrangler at/s. p_holmen@hotmail.com