160, 175 or 180-Degree Temp switch

I something broken or wrong?

A lower setting is only going to turn on the fan at a different time. It does not control engine temp.

Since your profile is blank it is impossible to give much in the way of information or advice.

 

No temp switch made prevents overheating.

A 79 with a good cooling system should be able to sit in a traffic jam in Riyadh in August with the A/C running.

If you want a bigger margin put in bigger better fans.

 

It seems to me that you would want your radiator temp switch to be selected to be a higher temperature than your thermostat.

I was having weird temperature problems and my radiator fan switch finally failed completely. This coincidentally happened right before my car ('88.5 328) was going in for a belt service.

Turns out besides the fan switch failing, the thermostat was stuck open. So the radiator fan switch was essentially setting the upper temperature limit but nothing was controlling the lower limit.

My mechanic installed a 180 degree thermostat and 195 degree radiator fan switch. The car has never run better! The coolant heats up to 180 degrees quickly, which the engine really seems to love. Most of the time the temp gauge is solid on 180, extended idling will cause it to eventually creep up to 195 and the fans will come on and cycle on and off keeping the temperature there until the car gets moving again and then it usually drops back down to 180 pretty quickly. Seems to me that this is how it should work. Now I never worry about it overheating.

 

I would say the same thing "It makes no difference" at the end of the day..

The system performance has far too many other factors, radiator condition, cooling hose age and thermostat at the motor..

Mine at full flow is 180 degrees, turning the fans on earlier won't buy you better flow.

 

If the stock cooling system is working as designed overheating isn't an issue.