Replacement for Faria Diesel Tachometer Sender Part Number 90901

Faria Discontinued this tachometer sending unit, but we found a replacement for it. It is a direct fit and wires right up to your existing 8 pulse per revolution tachometer.

Diesel engines require a sender (see below for detailed sender installation). You will need to connect the two sender wires to the tachometer; one wire to the SIG terminal and the other to the NEG terminal. There is no polarity between the wires, so each can be connected to either terminal. In installations where only a single wire exists from the engine to the tachometer, it is possible to connect the second wire from the sender to the tachometer ground through an electrical ground at the engine. However, this method is not recommended because erratic readings may result from electrical noise in the ships wiring.

DIESEL SENDER INSTALLATION: This Diesel Tachometer Sending Unit is a mechanically driven sender which attaches to the tachometer drive fitting found on many diesel engines and generates the electrical RPM signal. They fit the standard 7/8”-18tpi SAE tachometer drive. The units come standard with a 3/16” (0.187”) diameter round key drive. A 7/8”-18tpi SAE output is also provided on the top of the sender to allow a pass-through connection. The units produce 8 pulses per revolution.

Install the sender by screwing the sender nut onto the mechanical tachometer drive fitting on the engine. Position the drive pin so that the key engages the mating slot Tighten the sender securely so that it will not rotate from vibration. Maximum torque is 8 foot-pounds.

NOTE – damage due to cross-threading or over-tightening voids the warranty. When a mechanical cable is used to control another device, such as a synchronizer or mechanical tachometer, be sure to mount the mechanical sender directly to the engine. This will avoid fluctuating reading caused by “whip” in the drive cable. The drive cable may then be connected to the output fitting on the top of the sender.

The two black wires are not used for this diesel tach sending unit.