Problems with my CHT (cylinder head temp) gauge.

I have a k-type thermometer mounted on my 12v scooter with a k-type thermocouple running under the spark plug. Things were working ok until I hooked the setup on to the bike itself, powering from the ignition. Now the gauge just reads 0.00C or will rise up to temp and then quickly go back to 0.00. Anyone got any ideas? Is it a voltage/power problem? I've checked all connections. Unit seemed to be working fine on a 12v aux battery I had in the house.Any thoughts appreciated.

lemonie5 years ago
I'm interested as to why.
Have you drilled a hole in the head to poke it into?

Try insulating the t/c from the metal work somehow, or buy an ungrounded TC. quite often the meters rely on the Tc being connected on one side to the supply.

canucksgirl5 years ago
You should have 3 wires to it, right? The red should go to your pos battery terminal, Black needs to be grounded to the frame or battery ground and the 3rd (presumably a brown? wire) should go to your ignition switch. Is that how its hooked up? Off the top of my head (and past 12:30 am for me), I'm guessing its a power issue, as you said it appeared to be functioning before installation.