Thundercat temp light question

[fourbarrel]

My bud just picked up an 02 T Cat and yesterday was his first real run on it,other than a short one to try it out before buying it,and the temp light was coming on after about 10 minutes or so of riding.All together there was 5 of us,2 Doo's,2 Cats and my SRX and his was the only one experiencing any heating issues.The 2 Doo's each had temp gauges and they were normal and neither mine or the other cat(ZRT 600) were having any problems running hot as there was plenty of loose snow on the trails.
We tried bleeding the coolant bottle a few times thinking the system was air locked but every time we did this it made no difference in how long the machine would run before the temp light came on.We even took out the thermostat thinking that may be faulty but that made no difference.Do these sleds ever experience faulty temp sending units?I'm not familiar with cats at all and their electrical systems or faults but wondered if anyone here has any experience with these sleds.

 

[no1chevyboy]

are the heat exchangers hot?

 

[bolin22]

was the temp light on solid or flashing? i cant remember for sure but i think those flash codes using the temp light.

 

[fourbarrel]

Temp light was on solid and we tried to feel the entire heat exchangers for hold/cold spots but as far as we could tell they were hot all across their surface.
I was talking to my bud today and he told me he may have cured it of the heating problem anyway,he was out yesterday and it started to do the same thing and he said piss on it and run it.The temp light was on for a bit and then went out and never came back on so it may have just had an air bubble in the system somewhere that just had to work itself out.
We tried and tried to bleed the system but couldn't get any air out by elevating the front and burping the reservoir bottle,as I'm told that's how to do it with this sled.