Whelen: Service Update – M4, M6, M7, M9

The M Series lightheads have been updated to allow Low Power activation in the Steady and Signal Alert™ Steady patterns.

Low Power intensity has 5 levels. To select apply 12 volts to the power and low power wires, then use the Scan-Lock™ wire to cycle through intensity.

The Instruction manuals for the M4, M6, M7 & M9 have been updated and are attached below:

14187M9 14191M6 14190M4 14189M7

Please contact us with any questions