Build Stretched 1-Ton FJ40

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Firemedic831 said:
Looks great outside . As far as the fans they should work with just power and ground i would think ? I know with my sniper it works as a ground . so i run a hot to the fan and when i hit a certain temp the wire from the sniper grounds and the fan comes on . Kinda backwards from how i think
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These fans have 4 wires. Power, ground and two trigger wires. I’m not sure if these trigger wires are supposed to be grounded or powered.

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What did you fill the shocks too ? 200 lbs ? I think there is a wire for the temp fan controll, I dont recall if it uses a diff sender or if you just jump the main temp wire to that terminal. You would think the comp would pick it up internally but I remember we had similar issue with fans and I believe that was the solution, not sure what year you have but tthat was an 07' motor.
 
Looking at this diagram. The blue wire is override full speed. Run power to that wire and it should run wide open.

And I bet the sensor has to be at least plugged in.
 
peesalot said:
What did you fill the shocks too ? 200 lbs ? I think there is a wire for the temp fan controll, I dont recall if it uses a diff sender or if you just jump the main temp wire to that terminal. You would think the comp would pick it up internally but I remember we had similar issue with fans and I believe that was the solution, not sure what year you have but tthat was an 07' motor.
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I put in 150 psi.
 
clrussell said:
Looking at this diagram. The blue wire is override full speed. Run power to that wire and it should run wide open.

And I bet the sensor has to be at least plugged in.
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I don’t have that part of the wiring harness as I connected those wires to my PCM harness instead. I just have a 4-wire pigtail with no instructions.
 
Mike Shull said:
I don’t have that part of the wiring harness as I connected those wires to my PCM harness instead. I just have a 4-wire pigtail with no instructions.
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Your pcm is probably ground controlling the fans. I assume you are hooked into the factory fan control? Oem LS ecm and modified wiring? Or aftermarket harness?
 
Mike Shull said:
I don’t have that part of the wiring harness as I connected those wires to my PCM harness instead. I just have a 4-wire pigtail with no instructions.
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If you leave the white wires unhooked, or at least not grounded, can you hook the blue wire up for full power?
Or is that what you’re saying you don’t have?

Either way, the white wire looks like to me it would trigger a relay at the motor, but it sure doesn’t look like there’s room for a relay in there.
The main power draw is definitely coming from the red, and it doesn’t look like it’s switched through the ground. It’s all about their sensor and how they signal the fans.

ETA but your pcm may be designed to switch through the ground…
 
I don’t have the Spal sensor or blue trigger wire. My ECM has two ground circuits for two fans. I hooked those ground circuits to two 40 amp relays that delivers switchable 12v, and this is working correctly, though they could be tweaked as one fan comes on at 205°F and I haven’t measured when the second fan domes on, but the power wire was live at 225. I’d think that they should be more like 195/205.

I modified a factory harness and built my own fuse block and relays before I knew what fans I was going to use. I think that you all are on to something with the sensor that Spal provides. I sent them a message. I was wiring this based on a few posts that I found on Pirate (specifically for Spal fans) and the LS1 swap website. DeWitts couldn’t provide guidance on using the factory PCM trigger wires to turn on the fans.

If I haven’t burned anything up I’ll probably rewire with the Spal sensor, and possibly hook an override to one of my toggle switches on the dash.
 
I’m putting this link here for future reference for wiring Spal fans with either the Spal temp sensor or being triggered by a P/ECM. This person seems to be fairly knowledgeable though I will wait to hear from Spal before I try his methods. He suggests that when not using the Spal sensor, both trigger wires need to be used, with one hooked to + and the other to -.

It seems as if the white wire alone would need to be hooked to a PWM signal, which the Spal sensor provides.

As I read more, and thanks to Peezy’s chat offline, I am realizing that the $200 Spal sensor is preferable because it will run the fans at variable speeds based on the nature of the temperature (I.e. as the temperature rises, the Spal sensor signals the fans to continuously ramp up the percentage until the temperature stabilizes or reduces.). It seems as if these Spal fans, specifically the brushless design, are extremely efficient, though signaling them to be on or off may not be the ideal configuration as they may not properly regulate the temperature. I’d probably be fine if I were running a buggy in the hot desert 100% of the time, but it might be like a game of wack-a-mole when I’m driving through cold weather.

irate4x4.com

Cooling Fan Tech

Compiling all the cooling tech into one thread. Not limited to just fans. Brushless: Brushless fans are taking over the OEM and aftermarket and they are starting to show up on the newer ULTRA4 builds. The most common right now is the brushless Spal fans and they are easy to tell from the motor...
irate4x4.com irate4x4.com
 
So that means the Spal sensor provides the ground for white at the sensor, if not using Spal sensor then you provide ground to yellow, this makes sense, it just means the control module in fan grounds thru the sensor or yellow and the power supply at fans has its own separate ground.
 
Spal is amazing and I highly recommend using them based on their outstanding product support, and because their products seem top notch.

I’ve decided to start over with my fuse block and relays so more to come on that after this home remodel project is done (October?). I will be switching to a Spal sensor as recommended. Lesson learned not to get tunnel vision on a given path. Ha.

Here are summarized key points from my conversation with Spal:

1. Direct Wiring to Battery: Red/Black wires for the fans should be connected directly to the battery for constant power/ground, not through the PCM, any PCM-controlled circuit, or any power switching device like a relay. Switching the main power/ground on/off will cause the capacitor inside the fan to charge and discharge, which could destroy a 40A output from a PCM over time. Otherwise, damage to the PCM, the external relay, the fans themselves, or the entire system is likely.

2. Fan Wiring Configuration and Switching Control (Without Spal Temperature Sensor):
- Red: Constant +12V
- Black: Constant Ground
- White: Switched Ground. Use the white wire for controlling the fan by switching it on/off via ground.
- Yellow: Keyed +12V. The yellow wire should be connected to an ignition-switched +12V source to ensure it's only powered when the vehicle is on.

3. Operation Process:
- The fans will soft start and ramp up to full speed within approximately 10 seconds when properly wired.
- The white wire, when grounded, wakes the fan motor from sleep mode.

4. Recommended Setup: The manufacturer's diagrams recommend using a coolant sensor controller for fan operation to avoid running the fans at full speed continuously, with the white wire connected to the controller and the yellow wire not used.
 

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peesalot said:
That pitman arm drag link end is almost maxed out in that next to last pic. Might want to shoerten that pass side limit strap to be tight right there, IMO.
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That is supposed to be a long travel joint, though I had considered using a high angle heim joint instead.

[CORRECTION]: the steering joint is actually past the pivot point so that angle gets steeper as it articulates, but it still never bottoms out, but it gets close to being fully maxed at full articulation. I’ll keep an eye on it.
 
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