Most auto parts stores have pressure cap testers. It should hold about 15 psi. With a 15 psi cap and a 50/50 mix of antifreeze and water, boilover should not occur until at least 120C.

If the fans are operating properly is should never exceed 110C. What is the maximum reading you are seeing on the temp gage?

The electromagnetic engine driven fan clutch should engage at about 100C and you should hear it click. When engaged you should feel much more air flow and hear more fan noise when the engine is revved up. The electric fan should engage at about 105C.

As Peter said, the fuses are a good place to start, then check the temperature switches.

Duke