Instrument Panel Dimming

Battery voltage is applied at all times to the Headlamp Switch. When the Headlamp Switch is in "HEAD" or "PARK," voltage is applied through I/P Fuse #42 to the I/P and Headlamp Dimmer Switch.

The I/P and Headlamp Dimmer Switch controls the brightness of the Panel Lamps by means of a rheostat. When the Dimmer Switch is turned to the "MAX" position, the resistance is reduced to 60 ohms and the Panel Lamps are bright. When the knob is turned to "LO," the resistance increases to about 190 ohms, and the Panel Lamps dim. Chevrolet models use an additional module to control Instrument Panel Lamp brilliance.

SEO I/P Dimmer Switch
The SEO I/P Dimmer Switch is used to completely blank out the digital speedo cluster and Radio display. Applying voltage to CKT 1244 will cause the V/F displays to turn "OFF," with Park Lamps off.