cooling fan switch thread size?

[HUMMER H1]

Hey guys I am looking for a thread size for fan switch,
My humvee is 12v setup, I made a manual override switch to turn on the fan on demand, however I also need to replace the thermostatic switch to 12v, so it can turn on the fan automatically,

if I know the correct size I can order is from Napa.

thank you

 

[Mogman]

If you are talking about the switch that is in the water cross over I believe it is 1/2" NPT

 

[HUMMER H1]

If you are talking about the switch that is in the water cross over I believe it is 1/2" NPT

The thread size for this switch
It activates the hydraulic fan valve / the fan.

 

[Coug]

Isn't the cadillac valve still going to be 24V?
Or am I missing something?

 

[HUMMER H1]

Isn't the cadillac valve still going to be 24V?
Or am I missing something?

you are correct, I am using 12 to 24 converter for two items on the truck,

Cadillac valve and windshield wiper motor, everything else is 12v

 

[Coug]

Have you considered switching to a civilian style fan clutch setup rather than the military one? The only real advantage to the military one has to do with deep water fording, or possibly that it locks up 100% for a little more aiflow. It honestly seems like more hassle than it's worth for only those 2 items if everything else is 12V.

 

[Mogman]

I don't see where the the switch would care if it was running 12V or 24V as long as you do not exceed the current rating

 

[HUMMER H1]

Have you considered switching to a civilian style fan clutch setup rather than the military one? The only real advantage to the military one has to do with deep water fording, or possibly that it locks up 100% for a little more aiflow. It honestly seems like more hassle than it's worth for only those 2 items if everything else is 12V.

I have thought about it but very quickly decided that humvee style is much better,

humvee style hydraulic fan is 100% lock up setup just like large trucks.
The civilian style is not 100% lock up.

i also need to change the pulleys and a lot of things to make civilian style work, because humvee has 8 groove belt, H1 has only 5 groove belt

 

[HUMMER H1]

I don't see where the the switch would care if it was running 12V or 24V as long as you do not exceed the current rating

I am using two separate 12 to 24 converters, 10 amp each, super easy to install and they work great.

 

[Retiredwarhorses]

I have thought about it but very quickly decided that humvee style is much better,

humvee style hydraulic fan is 100% lock up setup just like large trucks.
The civilian style is not 100% lock up.

i also need to change the pulleys and a lot of things to make civilian style work, because humvee has 8 groove belt, H1 has only 5 groove belt

like all civilian style viscous fan clutches, it locks up based on temp flowing across the thermostat on the clutch, I’ve been installing these on trucks in my shop, so it maintains an overall lower temp, the OEM setup is on and off, doesn’t come on till 220, the OEM fan is a 14k CFM, it moves a massive amount air and lowers temp within 30-60 seconds, the problem is the end user, 99% of my customers are not ex-military hmmwv drivers or mechanics, they dont drive these trucks with the watchful eyes of a mechanic, meaning,…..when one of the components in the cooling systems fails “generally the thermostatic switch” ite too late for the motor, for the driver who fully understands this system and is the type that scans the gauges and listens for the fan engagement as part of the driving experience, than the OEM setup is fine.