4-24. ELECTRICAL SYSTEM - Continued
4-24.6 Instrument Control Panel Seitches - Continued
Air Switches (Fold-Down Panel) Replacement
These small air switches are used to set the truck mode and to operate the tank valve, CFR governor, water
educator, and foam valve.
Drain all four truck air tanks.
Hinge up the fold-down panel as detailed in para. 4-24.4 paragraph c.
Tag and disconnect the air line from all three ports on the valve.
Unscrew nut (1) from front face of panel Remove nut (1) and lockwasher (2).
Pull switch from rear of panel.
Remove fittings from valve ports and discard switch.
Install fittings in new air switch Coat threads with pipe sealant (item 22, Appendix E) prior to installation.
Install new switch in panel hole. Orientation of switch does not matter provided toggle operates up and
Install washer (2) and nut (1). Tighten firmly.
Reconnect air lines as tagged in step 3 preceding.
Fold back panel and install retaining screws.
Panel Lam Switch Replacement
Hinge up the fold-down panel as detailed
In para. 4-24.4 paragraph c.
Tag and disconnect wires from failed switch.
Loosen screw (1) and pull knob (2) off switch.
Remove nut (3) and washer (4).
Pull switch from rear of panel and discard.
Install new switch in panel hole. Be sure it is
in same rotation as removed switch.