Installation manual

1-29

90-898305

Installing Standard Analog Tachometer to Digital Optimax Engines

This procedure allows a standard analog tachometer to be connected to the

tachometer plug that is incorporated into the key switch harness.

NOTE: SmartCraft speedometer or tachometer communicate with the engine

through the gray lead and the brown/white lead in the key switch harness.

This procedure uses one of these leads to operate the tachometer and breaks

the connection between the SmartCraft gauges and the engine. SmartCraft

gauges will not function with an analog tachometer connected. The System

Monitor, Speedometer and Tachometer communicate with the engine through

a dedicated 10 pin connection on the engine. Using this procedure to install an

analog tachometer will not effect the operation of the System Monitor,

speedometer or tachometer.

1. Locate the diagnostic port plug mounted on the ECM. Remove and discard

the diagnostic harness from the port plug.

2. Install cover P/N 832948A1 on the port plug.

3. Locate the gray (tachometer signal) wire in the engine wiring harness. and

remove the rubber plug. Connect the gray wires together.

4. Connect tachometer to the tachometer plug using tachometer harness P/N

84-86396A8.

Note: Diagnostic harness (b) is no longer standard on engines.

Notes

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