Headlight Doors: Testing

A leak test on any part or component of vacuum system can be accomplished with the use of a vacuum test probe. Plug probe into system at desired point. The reading on the gauge should momentarily fall below 14" of vacuum, if there are no leaks in the system the reading should come back to 14" of vacuum and hold steady. To leak test headlight switch, attach vacuum probe to center (white) port, and cap the two outside ports. Move selector switch thru OFF-PART-ON positions and observe the gauge. The gauge readings should be 14" in all positions, if reading should fall off in any position switch should be replaced.