Engine revs when lights on

[daveclow]

I have a 94 7.3 IDI bus with lots of exterior lights. When I turn the headlights and clearance lights on, the engine immediately sounds like the rpm steps up. I don't have a tach so I can't tell. Is there a device that steps up engine speed to increase altenator output?

[insane3639]

im sure the engine detects a major amp draw its probably normal

[elibenson]

IDI engines don't detect a darn thing. Now it probably does have a charge protect system, where when the amps being drawn goes up, it triggers a vacuum solenoid that pulls the throttle lever. All the older ambulances have them. I would guess a bus would too.