HMMWV Contact truck weld switch

[Myrtleman]

I finally got around to installing a Schwend Waterjet keyed ignition today (great concept and product) and while I was at it, I was trying to decipher whether or not to remove a welding switch on my dash. Apparently this was a contact Truck with a welder in the back. The wire leads are labeled number 69 and number 70 and they feed up through the firewall and connect to where I have included a picture (time delay module). Excuse my ignorance for not knowing what these parts are called but this is my first rig and I’m learning every day. Is it safe for me to remove the switch and the leads and then just connect those two plugs together that the switch is currently hooked up to under the hood that I have pictured? I circled where it exits the firewall and I also circled where the leads are connected in the photo. I also included a photo of the back of the switch and the labeled wire leads under the dash. Thanks for your help

 

[Mogman]

It looks like someone wired the switch to manually control the fan clutch, yes you can remove it but if it will enable (override) that automatic control some would think that is a plus.

 

[Myrtleman]

Mogman the switch has been locked to the weld off position. Is that potentially affecting my fan at the moment? I’m just a little bit nervous about removing it or changing things. Like I said I’m definitely a newbie with these rigs so apologies in advance for any over cautious concerns or questions. Thanks again

 

[Mogman]

The way the switch is wired the switch is closed, this should give you normal fan operation, if you pull the handle out you should be able to switch it, unless it is stuck, the switch is a SPDT (single pole, double throw) so it can be wired on or off with the handle down.

 

[Mogman]

Actually it looks like you can remove the switch by simply unplugging the two connectors and just plug the connector from the TDM into the connector for the Cadillac valve.

 

[Myrtleman]

Actually it looks like you can remove the switch by simply unplugging the two connectors and just plug the connector from the TDM into the connector for the Cadillac valve.

That’s what I was thinking. Are those connectors normally plugged into each other from the factory?

 

[Mogman]

That’s what I was thinking. Are those connectors normally plugged into each other from the factory?

Yes.

 

[Retiredwarhorses]

I’ve had a truck with that same switch, it engages the fan clutch if it not yet turned on via the thermostatic switch, the switch is a safely switch, you need to pull the switch to move it from position to position.