New RPM gauges not working. Faulty signal?

[mahlzeit]

Hello, recently bought a 2003 lx210 and none of the gauges worked. I'm fine on fuel and speed by now, but having issues with the tachometers. Bought Faria gauges with hour meter (THC617B) and hooked them up. One of them showed some erratic life (needle would go way up and then go back and forth) but now doesn't show any RPMs at all. Other gauge didn't show anything from the get go.

I tried to check the signal and wiring with my limited knowledge. I am pretty sure the gauges are hooked up correctly. They have power (lcd hour meter comes on and shows 0), also backlight works as expected.

When checking the rpm signal with a Hertz meter, it shows about 400Hz on a freshly started idling engine (which seems to high, as this should translate to about 8k rpm if I'm doing the math right) fluctuating quite a bit. When increasing the throttle slightly it actually goes DOWN and stabilizes around 200Hz.

Quesitons:

• Does the signal seem correct?
• If not, what should it show? Where can I check? What could be wrong?
• could a faulty tach signal damage the gauges? Neither of the needles shows any life, even though there is clearly an (erratic) signal

Video of signal: Streamja - Simple video sharing

 

[Bruce]

Did you adjust the input setting on the tachometers to match the engine output?

 

[mahlzeit]

Did you adjust the input setting on the tachometers to match the engine output?

Yes, set it to 6, which should be correct for a three cylinder 2 stroke engine, as per my understanding.

 

[Bruce]

Yes, set it to 6, which should be correct for a three cylinder 2 stroke engine, as per my understanding.

That sounds right but I suggest trying other options. I remember there was some fiddling with mine to get them right but that was 9 years ago.

 

[4x15mph]

I remember the setting requiring 6 cylinder as the setting but I think there were a couple of options. As stated above, try changing the setting. Another option would be to call Faria as I bet they would know what you can check as far as input electrical signal.

 

[the MfM]

Been a while since I messed with mine. But I think you need to use the 3p/6c setting.

Grey was the signal from the sender. Then you need 12v from the the ign switch and a ground to the tach.

There’s a fourth wire for the gauge lights. I remember the 12v input and the lighting wires were reversed on the new gauges. So I had to cut the factory harness and switch those two wires.

 

[mahlzeit]

Everyone, I am an idiot. I thought setting "6" stood for 6 cylinders. But it even says on the back of the gauge itself that 6cyl/3p is setting 2. Switched it and everything is working.