Tachometer question

[ronrymanr]

2003 Volvo penta 3.0 GL. New member Geeetings to all .New to my wife and I four winns freedom 180. 2nd owner. Tachometer not functional. 1.Is there a flywheel sensor or pickup on the coil, or alternator. Am I looking for a gray wire.Any ideas for troubleshooting? While relocating wires laying in bilage area I found a female plug with 3 wires 2 purple and 1 black? I ordered a shop manual but want to use the boat now. Any options or ways to troubleshoot. Appreciated.

 

[Ian_Edwards]

I don't know the engine, but most tacos take the signal from the W terminal on the alternator.
Try looking a wire from the W terminal and trace it back.
The taco also needs a 12v power supply, are you sure it's getting 12v?

 

[Leighb]

Some Volvo engines have a Tach sender on the injection pump, our TMD40s do, the spade connectors get loose/dirty and need refixing.

 

[VicS]

2003 Volvo penta 3.0 GL. New member Geeetings to all .New to my wife and I four winns freedom 180. 2nd owner. Tachometer not functional. 1.Is there a flywheel sensor or pickup on the coil, or alternator. Am I looking for a gray wire.Any ideas for troubleshooting? While relocating wires laying in bilage area I found a female plug with 3 wires 2 purple and 1 black? I ordered a shop manual but want to use the boat now. Any options or ways to troubleshoot. Appreciated.

Its a petrol engine .

Diesel engines usually have a sensor looking at the teeth on the flywheel or a gear wheel in the timing / injection pump drive train or use a signal from the "W" connection on the alternator

ITYWF that on petrol engines the tacho usually uses a signal from the ignition system

Id be looking at the ignition module and the coil for the connection

 

[coopec]

2003 Volvo penta 3.0 GL. New member Geeetings to all .New to my wife and I four winns freedom 180. 2nd owner. Tachometer not functional. 1.Is there a flywheel sensor or pickup on the coil, or alternator. Am I looking for a gray wire.Any ideas for troubleshooting? While relocating wires laying in bilage area I found a female plug with 3 wires 2 purple and 1 black? I ordered a shop manual but want to use the boat now. Any options or ways to troubleshoot. Appreciated.

Here's a couple of links that may help:

Volvo Penta Tachometer Trouble - Cruisers & Sailing Forums

RPM meter not working - Cruisers & Sailing Forums

volvo penta tachometer wiring Page: 1 - iboats Boating Forums | 558444

 

[pvb]

2003 Volvo penta 3.0 GL. New member Geeetings to all .New to my wife and I four winns freedom 180. 2nd owner. Tachometer not functional. 1.Is there a flywheel sensor or pickup on the coil, or alternator. Am I looking for a gray wire.Any ideas for troubleshooting? While relocating wires laying in bilage area I found a female plug with 3 wires 2 purple and 1 black? I ordered a shop manual but want to use the boat now. Any options or ways to troubleshoot. Appreciated.

Welcome to the forums!

You should find that the tacho is driven by the grey wire connected to the ignition coil.

 

[VicS]

Welcome to the forums!

You should find that the tacho is driven by the grey wire connected to the ignition coil.

Did you just read that on the mobo forum 2003 Volvo penta 3.0 gl tachometer operation question

 

[pvb]

Did you just read that on the mobo forum 2003 Volvo penta 3.0 gl tachometer operation question

No, I don't look at the mobo forum. I saw it on this diagram...