Thermal switch

[ham1974]

I bought a summit racing fan relay and the switch is bad. If you ground the wire the fan comes on so I know my relay is good. I have read that these things take a crap quit often. Is there a way to test with an ohm meter? This one has just the one spare connector. Also I installed it in back of intake if that makes a difference.

 

[fleming442]

I run the Painful 2 wire, and have had one fail as well. I wired in an override switch in case it happens again.
Did yours ever work, or just quit?

 

[ham1974]

It never worked first time using it. I just wonder about the intake temperature in back if it maybe runs a lot cooler. I let it get up to about 230 before I shut it down. I think it supposed to trip at 185.

 

[pontiacgp]

Check the engine ground

 

[fleming442]

Did you Teflon the threads? That will kill the ground...

 

[ham1974]

Did you Teflon the threads? That will kill the ground...

I check that don’t think did. It is an aluminum intake. I have a good engine ground on back of head bolted to frame.

 

[olds307 and 403]

All these aftermarket fan controller's suck. The thermal switches fail or the relays themselves. Maybe it is the amperage draw of my Stratus fans but the last Flexalite fan controller didn't work at all.

 

[pontiacgp]

I check that don’t think did. It is an aluminum intake. I have a good engine ground on back of head bolted to frame.

you should check to make sure you have a good ground at the switch with a multimeter

 

[UNGN]

All these aftermarket fan controller's suck. The thermal switches fail or the relays themselves. Maybe it is the amperage draw of my Stratus fans but the last Flexalite fan controller didn't work at all.

Starting a high amp fan on 12 volts will really load a system. The amp draw is super high until the fans get to their natural speed. Even with a controller (unless it was a PWM controller), I would have the controller turn on cheaper, replaceable relays.

I try to run dual fans in series then switch to parallel when the motor gets really hot. Dual fans in series draws very low amps, and since they are already running at 1/2 speed, the amp spike is less when they switch to full speed.

The only drawback with this (other than needing an extra relay), is if one fan dies, both fans die... until it gets hot enough to switch to parallel, then the good fan will kick on.

 

[ham1974]

Well I took off the thread tape. No difference so I ordered another switch. https://www.amazon.com/gp/product/B018LQAEX2/?tag=gbody-20
Still will not work maybe because I have it screwed into an aluminum intake? I assume the switch is grounded as it comes on when the thermal wire is grounded. Suggestions?