Tweet
The Yamaha multifunction tachometer on my 2001 150HP HPDI suddenly stopped working. Have checked all visible wiring and see no loose or corroded connections. The trim/tilt and oil indicators continue to work correctly but RPM shows 0. On occasion, at startup when cold, I will get a reading for a short time but usually less than a minute then 0. Where should I look next?
-
-
the tach signal on that motor is generated by the ECU.
start tracing the green tach send wire back to the ECU.
are there any High idle issues ? -
Thanks. I will attempt to (unbundle) trace the tach wire from the helm to the engine. No other engine problems. Runs and idles fine.Comment
-
Still can't figure it out. Wiring from the ECU appears intact. In addition to the pin harness, there is a separate green and green/red coming from the helm with a snap plug just inside the engine. The green/red connects to another green/red but the green connects to a red/black. I do not get continuity from that green to the solid green coming out of the tachometer, but assume there is another green in the pin harness. The charging circuit is working and I have over 13V at idle.Comment
-
The green wire in question runs from the ECU in the main engine harness to the ten pin connector. From the connector it connects to and runs within the main ten pin harness to the key switch. From the key switch the tachometer signal wire runs to a mini harness that runs to the tachometer. The tachometer green wire is the single wire with a bullet connector on it.
Forget about any other green wires that may or may not have other colour tracers on them. Yamaha is notorious for screwing up wire colours and changing colours across connectors.
Comment
-
Looks to be pin 34 at the ECU that picks up the tachometer signal and carries it to the engine harness side ten pin connector.
Comment
-
Thank you so much for this information. It's about 97 degrees outside now so I'll have to wait for cooler weather to chase this down. The diagram is very helpful. It's very tight under the console so I will have to unbundle and separate the green wires. I have located the green bullet connector that plugs into the mini harness.
In the event that all of the wiring checks out, any other suggestions that might have caused the tach to suddenly stop working?Comment
Comment