MAINTENANCE AND LUBRICATION 269 This is a 12-volt, unswitched battery power connection. It can be used to power external devices that require power at all times, even when the key is turned off. This source is protected by a 20-amp circuit breaker.
Ignition Post (IGN) This is a 12-volt, switched battery power connection. It can be used to power external devices that require power only when the key is turned on. This source is protected by a 15-amp circuit breaker. Ground Post (GND) This is a ground connection. It can be used as a power return connection for external devices.
WARNING The tachometer output, speedometer output, and serial links A and B are for specific hookups. These terminals should be used only for their specified purposes and connection to these terminals should be done only by a qualified service technician. Note: The tachometer output and speedometer output are 50% duty cycle, Transistor-Transistor Logic (TTL) compatible, square wave signals that are calibrated to provide a standard pulse rate of 12 pulses per engine revolution for the tachometer output and 30,000 pulses per mile for the speedometer output. TTL compatibility of these outputs may be affected by other devices connected to these outputs. Tachometer (RPM) Output This terminal is to be used for devices requiring information for engine speed signals. (See the Warning and Note above.) Speedometer (MPH) Output This terminal is to be used for devices requiring information for vehicle speed signals. (See the Warning and Note above.) SAE/ATA J1708 Posts (Serial Links A and B)
