Just got an 89 CBR 600 last week. I finally got tags on the bike and took it out for a ride. Feels pretty good for a 20 year old bike... a bit of a flat spot at 4K some times, but nothing major... the bad thing was the temperature gauge stopped working about ten minutes into the ride. Any tips on what to troubleshoot first? Is that the coolant temp sensor on the left hand side, visible through the slot in the fairing, or is that the fan switch? I thought I would ask some opinions before I take the instrument cluster apart. For what its worth, the fan does cycle on and off as it should.

THANKS

 

One more thing... I just went into the garage and looked.. the temp gauge is rising up off the needle a few millimeters, so it is registering something after all. Maybe a bad sending unit?

 

Did it stop working or is it just registering a low temp?

Once the coolant really starts circulating unless it is really hot my gauge stays very low on the scale. I think the gauges are infamous for either reading (basically) 0 or halfway up the scale.

KongBastard

 

It could be that when I was riding it dropped down and was just sitting right above the peg... When I turn the key and the engine is warm, you can see the needle move slightly which makes me think it is getting current, but it never goes past that point anymore. On my 90 CBR 600 I remember the gauge showing about 1/4 to 1/2 most of the time, not so low.

THANKS

 

I looked up in the manual how to test it. You can find the manual somewhere around the forum here.

1) Remove fuel tank.
2) Disconnect the sensor wire from the thermosensor, and short it to ground using a jumperwire. (by your rad cap)
3) Turn ignition switch on
-the needle should turn all the way to H
Caution do not leave thermo sensor wire grounded for more then a few seconds, or the gauge will be damaged.

If gauge does not move check sub fuse (10A) And all wires for a loose connection or open circuit. If everything is normal, replace gauge

 

Thanks for the info.. I rode it to work this morning to see what the gauge would do, and it is WORKING FINE again ! I don't know what the issue is, but maybe this weekend I can pull up the tank and look at that sending unit and also the fuse. I appreciate the directions.