Hello,

I was wondering if someone was familiar with an aftermarket radiator that had a retaining nut (very large, close to 1 and ½ inches) holding in the fan temp switch? This radiator is an all metal type.

My switch does not seem to be working and I was going to replace it. I was wondering if the nut was just blow out protection and if there was any unique gaskets/rings under this nut before I take it off. The switch doesn’t work, but the thing doesn’t leak. I’d like to know if I need any additional parts (other than the new switch and rubber grommet) before I take it apart and possibly ruin something (gasket/ring) I cannot readily buy. I am hoping it is just a nut-ring that prevents the switch/grommet from blowing out.

TIA

Dear brickie,

Hope you're well. Are you 100% sure that the switch has failed? Please note that the electric fan runs only when needed. Thus, it will come on most often when ambient temperatures are high, e.g., Tucson, AZ, USA in July or Darwin, NT, Australia in January. In such places, it is especially likely to run when airflow around the engine is low, e.g., in stop-and-start traffic. In cooler regions, the fan will run little, if at all.

That said, if the switch truly has failed, figuring out how to remove it might be easier, if the radiator's maker were known. Are there any markings on it? You might need to remove the plastic housing for the electric fan, which covers the top edge of the radiator. On the factory-installed rads, the plastic fan shroud is secure by three fasteners at the top of the radiator. The shroud has tabs at the bottom, that seat into recesses in the rail, on which the radiator rests.

If there is a manufacturer's name, you might contact them. Alternatively, someone at a radiator repair shop might need only a quick glance at the rad, to know how to remove the locking ring, and what is behind it. If the switch were screwed into the radiator, there'd be no need for a locking ring. Thus, I'd expect to find a grommet, into which the switch is pressed.

Hope this helps.

Yours faithfully,

Spook

I've seen the fan not come on and the engine start to over temp. When this happened, I pulled the wires off and connected them and the fan came on. (ruling out relay/fan) The scary thing is that the switch, or at least it’s back contacts are loose. In other words, I can pull the wires off and when I hold the flat spade switch connectors, the whole back side of the switch can move around. Knowing how the stock setup is, I do not understand how this can move around and not leak. (thus my worry that the retaining nut thing has some sealing or other property to it.