RTV900 temperature gauge probem


New member
I was doing a radiator flush and as I was warming the engine up I realized the temperature gauge wasn't moving at all. I haven't had this RTV very long. I have never seen it over heat but just hadn't realized that the gauge apparently does not work at all. When the headlights are turned on the gauge lights up so I know it is getting power. Is there a way to know if the gauge is bad or if it is something else? What else could it be?


Site Supporter
take the wire off of the sender and with the key on engine off use a test light to see if you have voltage to the wire. if you do then touch the wire to ground and see if the needle registers. if you do have voltage and the gauge reacts to ground then your sender is faulty.


Senior Member
Staff member
I have a 15 year old RTV900. I have to run it pretty hard for at least 15-30 minutes before I get any indication on the temp gauge. Short trips or no/low loads won't register anything.


New member
I got it fixed - it was the gauge. I bought a copy of the service manual and followed it's diagnostics. I used a multi-meter to check the resistivity of the sensor and it returned values that made sense. I got a voltage reading from the lead to the sensor, but it was less than 1V, and the manual says that if this lead does not have a voltage of ~12V to check fuses, wire bundle or the gauge itself. All fuses were fine and the wire bundle looks OK where I can see it so I thought I would start with the gauge. I opened it up and it is a very simple circuit board with only 6 or 7 components on it. Some of the soldering didn't look very good so I touched up all the solder points and re-installed. It works now.