2008 MXU500 Camo , Radiator Fan stopped working , replaced parts won't come on

[JimDirt]

I have this issue that started about a month ago  , the radiator fan suddenly stopped working  , its been averaging 100 degrees F here , and basically I can't use it without the fan functioning , I have removed and tested the Fan , it works when 12 is powered to it directly , so I know it is fine  , so then I replaced the Thermal Switch in the radiator , still the fan won't come on when I let it sit there and idle till I am concerned its going to overheat , so I ordered (a used) Fan EMI Filter that controls the fan , nothing changed , so I ordered a NEW one , it just came from Poland (only place I could find a new one , nothing here in the states) , I just plugged it in and let the thing sit there and idle till I was sure it was going to overheat , and the fan never kicked on  , even usually when you shut off the ATV and then turn the key back on , the fan would always come on till it cooled down  , but not now  , I know if I take a Power Probe Tool , and tough it to the Ground side of the Thermal Switch , and hit the Ground button , the fan will come on  , but I can't find (with all the plastics on , where the ground wire actually grounds to the chassis , and the wiring diagram doesn't help locate it (I have the Factory Service Manual PDF (for the MXU500 , 300 and UXV/SxS 500 in the 2005-2008 range of years , as I used to work at a Kymco Dealer)

Anyway , since I don't know where the ground point is , (all connections in the battery area are good) , I don't know if I should add a ground wire to the Thermal Switch to a close grounding area and call it good (guessing this would solve my issue) , or do I tear the wiring harness apart trying to locate where the issue is  , everything else seems to work as normal , so I am not sure , since several things are tied into that ground , so I can't figure out why the fan isn't working , but everything else seems to be functioning fine

Any Ideas , Since I replaced the 2 of the 3 components of the fan system and I tested the fan and know it works on its own  , what is left I am missing ..

[Ruffus]

Well, if you really cannot find the culprit, and you need the vehicle, make a direct line with an on/off switch from your battery or switched plus to the fan.

[JimDirt]

Well, if you really cannot find the culprit, and you need the vehicle, make a direct line with an on/off switch from your battery or switched plus to the fan.

Yeah , but I don't want the fan running all the time , or have to figure when to turn it on , since the Camo/Limited Edition MXU500 doesn't have the Temp Gauge on the dash like the regular models do (makes no sense that the lesser models have the temp gauge but the Limited doesn't) , and the EMI Filter is in the system for a reason , so not sure I want to bypass any of that and overheat the fan , or anything  , just was wondering if anyone had the same issue and they figured it out , or happened to know where the ground source is on the frame other than at the battery ...  , but thanks for the reply ..

EDIT:
OK , I hooked a Ground plug to the existing ground plug on the Thermal Switch , basically tied it into the existing wiring plug , and just added another ground going to the front Rack bolt that is directly on the frame (the same spot where I did my testing using my Power Probe tool) , and the fan still didn't come on  , so this is confusing , since the EMI Filter is new and the Thermal Switch is new , and like I mentioned , I hooked the fan directly to power (using my Power Probe tool) and the fan works , so not sure what is going on , unless its not getting hot enough , when I'm testing to activate the Thermal Switch  , so maybe tomorrow I will go to Harbor Freight and get the handheld Temperature gun and see how hot its getting , so I know if it should be kicking on or not , or if I'm not letting it get hot enough , as it should work with everything I replaced , although just looking through the Service Manual again , I noticed it shows the EMI Filter but it does not mention it in Testing , it just mentions the Water Temperature Sensor on the engine , but nothing about the EMI Filter relay

EDIT EDIT: 8-3-2024 1:05pm Central Time
OK , I just checked it with the Thermal Temp Gun and I guess I wasn't letting it sit there and idle long enough  , it took a while to get up to temp even in 94 degree F outside temperatures , so I then disconnected the EXTRA ground I added and plugged it in just as its supposed to be OEM and the fan stayed running , then as soon as the fan ran for a couple minutes it shut off and the radiator temp was lower  , so its working as it should  , so it was either the Thermal Switch or the EMI Filter , not sure , but I replaced them both for under $100 , so that was good ...... , Either way , the problem is solved .....