It is attached to the wiper motor.
The board is under the cap in the Wiper Motor.
There isn't a control board - the controls are all in the switch.
if it is like my older model chev truck there is a circut board in the wiper motor assembly, (under the hood), that needs to be replaced. You can get the part at any auto supply store.
It can be either integral with the alternator or be part of the on-board computer.
Trouble code P1870 means: Transaxle Component Slipping (4T60-E)
on the dash board
usually in top right of fuse board
Replace the paulse board that's attached to the wiper motor.
under the air vent next to the windshield on the outside of your car
Left Front Speed Signal Missing - possibly ABS related - will research more
Fuel filter for 1995 Chevy Van is located underneath driver's side door at running board.
The fuel filter is located on the frame rail on the drivers side. It is an inline type, and may be either a threaded type of be held to the fuel line with clips.