So I have this single, 3 wire, e fan and I'm trying to decide if there are two different speeds. It appears to me that both wires (one blue, one black) give the same speed.
any experience wiring one of these beasts would be helpful.

I'm also looking for a wiring diagram for the fan, thermostat controller, relay. There are so many to choose from. I just dont want to bun anything up while on the road.

Thanx

 

The Mark VIII fan is two speed. I think the green is low. Black is ground Blue is hi.
You will need to run the low speed because hi draws well over 40 amps and will melt most aftermarket controllers.
Check the FAQ section and read all about efans.

https://dodgeforum.com/forum/3rd-gen-ram-faqs-133/

Oh yeah, welcome to the forum.

 

Thanx for the welcome. I belong to a couple of other dodge forums as well. I did read the FAQ section on e fans and couldnt find a definitive answer.
What I have is two black wires and a fadded green or blue.
one of the black wires is the neg.
so I should only run the low ( if i can determine which wire ) and not the high

I am going to use a 70A relay withe the t-stat controller because i read there is a big spike when the fan is initialized

I like the looks of your truck.