WINDOW

RPM ACTIVATED SWITCH

PART NO. 628

INSTALLATION INSTRUCTIONS

Parts Included in this kit:

1

RPM Activated Switch

Part No. 628

1

“U” shaped crimp-on wire terminal

1

#6 x 1⁄4" sheet metal screw

2

#8 x 1⁄2" sheet metal screws

General Information............................................................ ...1

Mounting Procedure........................................................... ...2

Wiring Procedure...................................................................2

RPM and Cylinder Setting Procedure....................................3

Wiring Diagrams for the RPM Activated Switch

CONTENTS

Connecting to a Timing Retard............................................8

Connecting to a Timing Control...........................................8

Connecting to a Light...........................................................8

Connecting to an Electric (Shifter) Solenoid.................. .....9

Connecting to a Nitrous System........................................10

Connecting to a Nitrous System and Timing Retard.........10

Shifnoid Wiring............................................................... ...11

The Mallory 628 Window RPM Switch is an RPM switch that is triggered from the tach terminal available on most

aftermarket performance ignitions. It will not only activate at a particular RPM, but can also be set to de-activate

CANNOT be triggered from points or electronic distributor. It must be triggered from a tach output terminal.

The 628 features two independent sets of switch contacts that switch other devices on or off when the selected

RPM is reached. These contacts draw a maximum current of 5 amps. To switch more than 5 amps, you must use

the RPM Activated Switch output to drive a high current relay, such as a horn or headlight (see illustrations).

NOTE: The switch contacts are NOT connected electrically. This allows you to turn one circuit on and anoth-

er off at the same RPM.

GENERAL INFORMATION

®

MOUNTING PROCEDURE

Step 1

Disconnect the battery (–) cable to cut power to the system.

Step 2

Mount the unit in an area away from hot engine components or extreme heat, such as exhaust manifolds, and

away from moving parts, such as fans, belts, and linkages.

Step 3