Running wire for tranny temp gauge

Hello all, first timer here.

I would like to add a transmission cooler and temp gauge to our '00 Windstar. Can anyone tell me what is the best route for running the sending unit wire from the dash to the transmission? Is drilling typically required through the body or is there existing holes for running wire?

Also, any thoughts on whether to place the temp sensor in the transmission test port (assuming it has one) or in the line feeding the cooler?

Sorry if my ignorance shows, I am very much a greenhorn

Thanks,
Doug

hello feistranch!

I've sent wires through the firewall by tunneling through a rubber seals that heater pipes and pedal cables go through.