[Nitrogen]

when you switch on the AC do you hear the electric cooling fan switch on ?,
when the AC is on the high speed fan should always be running
the fan also runs at low speed with a seperate relay ( the relay in you pic could be for low speed fan) i would need to check the wiring diagram

 

[Nitrogen]

no i don't mean the blower motor,
the engines cooling fan at the radiator works on low speed and high speed so there are 2 relays,
if your cooling fan comes on at 106° then switches off after a couple of second maybe your temperature sensor is faulty normally the cooling fan is on for a couple of minutes not seconds ?

 

[Nitrogen]

that last pic is the resistor for the high speed fan relay you can just ignore the resistors and the high speed relay for now, just reinstall them and forget about them they are not your issue,
when you run the engine upto temperature and the fan kicks in it is imossible for the cooling fan to cool down the engine in just a couple of seconds, it takes at least a couple of minutes,
i mean engine temperature sensor,
are you sure you have removed all the trapped air from the cooling system ?
how did you check the low speed relay in the TIPM ? although i'm sure it is fine,
in this order i would check for
1, trapped air in the cooling system
2, faulty thermostat
3, a faulty engine coolant temperature sensor
4, your actual cooling fan is faulty,

 

[Nitrogen]

pretty sure there is your problem the "new thermostat", several members on this forum have had issues with aftermarket thermostat,
simple test is to run the engine upto normal temperature, stop the engine and quickly check that both the top and bottom radiator hoses are the same temperature (very hot),

 

[Nitrogen]

how did you get on with this ?