Fan Overide Switch SES Light Comes On?

[94LuminaZ34]

I wired up my secondary fan to a switch and now when I turn on the switch my Service Engine Soon light comes on? All I did was hook the wire to the 86 terminal of the relay so that the switch will control the ground path. Has anyone else had this problem? Did I wire it wrong?

 

1994 Lumina Z34 3.4L

[rockfangd]

The secondary fan is only supposed to come on at coolant temps over 235*f or if the AC is running. The only way to wire the fan into a switch is to disconnect the plug and wire in a ground and a switched wire and then it will be bypassed on the factory harness, otherwise there shouldnt be a light