Cooling system changes

Here’s the northern unit. I’m making brackets for the bottom mount and using this universal chrome thing I had laying around for the top mount.

Here’s the monster flex a lite setup that’s destined for the shelf for the time being. I paid $800 for this setup brand new.

Fan assembly temporarily attached with zip ties to check fit while making brackets.

On the shroud is where I mounted the controller. My battery is in the back so I ran the power wire to the solenoid. The ground was ran to the back of the block where I have a neg cable that runs back to the battery. I’ve wired up the ac controller and that’s been checked and it works by running the fans at 50% whenever the compressor clutch is engaged.

I have not run it up through op temps yet. Called it a day for now. I need to mix up some more coolant. I also got a decent volume overflow bottle that will be mounted in the spot where the battery used to be. As for the overflow tube for the bottle, I’m pondering running it way back to the center of the rear bumper. I’ve experienced coolant puke before and it wasn’t fun having the rear tires doused while at full throttle. I fixed the condition that caused the puking long ago but if it ever happens again, my tires will stay dry. Puke tube to the rear bumper from now on.

On the DCC controller there’s a connector for the ac circuit that runs the fans when the ac compressor is engaged. It’s the blue wire and I have that hooked up and it’s working. On the the same little harness plug there’s also a green wire. This green wire was not mentioned in the installation instructions.

Does anyone know the purpose of this green wire?

Rt jam, you are right, I missed that in the instructions. Pin 13 is for measuring the controller set point. This controller came set from the maker for a 180 thermostat and that's what I'm using now so there no need for me to make an adjustment there. I understand the debate between 180 and 190. Typically I run the factory 192 but since my ECM has a tuned chip and I'm running a Vortec blower I'm far from stock setup. I know that sometime running a colder thermostat can make an ECM not reach closed loop and turn control over to the O2's. But again, In my case I'm custom tuned and I have verified with my wideband 02 that my A/F ratios are where they should be in all driving conditions so I'm not negatively affected by running a cooler thermostat. On a stock or stockish setup, especially one with a stock configured ECM, I agree with you that the factory 192 thermostat is best.

Anyway, everything is working great. Northern radiator, Contour dual fan assembly, DCC controller, Dorman overflow bottle are all working great! I'm not sure how this controller knows when you shut the engine off but it knows. I suppose it recognizes the alternator is no longer spinning and battery voltage is all that it sees. While the engine is idling at operating temp you can hear and watch the fans gradually speed up and slow down as the controller maintains the temperature. The temp gauge needle stays steady in the same spot unlike other systems where the controllers allow the engine to heat up before triggering the fan, then cool the engine to a certain point before shutting the fan off. Not with this controller though. Steady temp constantly. The only time I saw the temp creep up a bit was after some hard acceleration runs I was doing to test traction issues I've been working on. But as soon as I resumed normal driving the temps came back down quickly. I also bought and installed the LED indicator that's offered by the maker. It lights up when the fan starts running and changes color according to the fan speed. Green at the lower speeds and changed to yellow and then red as the fans move faster.

It's pretty cool. For instance, if the fans are running at a higher speed when you shut the engine off, the fans will still run initially but they ramp down gradually and eventually stop. This happens within 10 or 15 seconds of turning the engine off. So you see, threre's no ignition source wire to this controller telling it when the key is on or off. It just senses voltage some other way and automatically knows the engine is not spinning.

The overflow tube runs all the way to the rear bumper. It looks pinched by the zip tie in the second picture but its not choked

Interesting because on mine there is no ignition source wire to tell the controller when the key is on. And like I said, the fan runs after you shut the engine off but only for 10 seconds or so. Seems to me if it were temp controlled only, wouldn’t the fan run longer than 10 seconds?