my coolant fan not coming on
Check fuses and relays? If they are all good then it could be a temp sensor switch or the fan has bad ground or fan motor is bad
I believe you that the fan(s) are not coming on. But if the car overheats at highway speeds, 50+ mph, the overheating problem is elsewhere. There is more than enough air-flow at ..say... 45 to 50 mph (probably even less) to cool the radiator and make the fans redundant or useless. Begin with checking the coolant level -- cold --- do not pop a hot cap. If it is good, next is thermostat to be checked. But if all this is moot and it does not overheat at speed, only at idle, then right back to Rob's answer
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