adventr
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The 100+ degree heat called for some cooling upgrades. Of course, I decided to do that when the heat was already here, so that made it fun working in my garage (not air conditioned). :sigh:
My H3 runs cool around town and if you're moving at all, but there are certain situations that cause the temps to climb quite a bit. Like sitting in a line of cars at a drive-thru at 5:30pm. Beating sun, black pavement, a/c blasting and other vehicles in close proximity really make for quite the heat load on the cooling system!
Friday afternoon I experienced just that. Ambient temp was 100f, vehicle was showing outside air temp as 110, intake temps were 140f (and that's WITH a snorkel...). Line was slowly moving forward, so I had just left the rig in Drive which means engine speed was at 625rpm. At that engine speed, the mechanical fan just doesn't move enough air to keep everything in check. Keep in mind, that I do have my H3 programmed to raise the idle to 850rpm when engine temps get above 200, but that's only with the transmission in park or neutral. When I moved the shifter to N, engine speed picked up and the mechanical fan brought the temps back down. But it's not always convenient to have to keep moving the shifter to keep temps in check.
Highest coolant temp that I saw while sitting in that line was 221f. Trans climbed up to 210, and engine oil temp remained about where it always does (225f). One very interesting thing to note, is that even with the actual engine temp at 221f, the "temp gauge" on the cluster was still showing just a hair under the half mark! Just something to keep in mind, as I frequently see people on here stating that "temp gauge never rose above half."
Anyway, in my opinion 220+ is too hot, so I decided to add a fan.
Simple way would be to just mount one up and put it on a switch or something. I wanted something better than that, so I went a little overboard.
Used a SPAL 12" Pusher (Their most powerful 12" model, straight paddle blades), and a PWM speed controller from a Chrysler (LOL). My factory PCM is able to output a PWM signal (for fan speed) based upon maps that reference engine coolant temp, A/C pressure, Trans Temp, Vehicle Speed..ect.
So basically, the computer controls the fan in the same manor as it would on a C6 corvette (same PCM). PCM reads sensors, references the maps, and then requests a fan % based on those maps. Aux fan ramps up slowly to the requested duty cycle (%). Aux fan speed only reaches what's needed to keep everything in check! Not running full blast all the time like it would be if on a toggle switch or something.
Here are some pics. You can see in the first pic that I had my trans cooler lined out for that space in front of my condenser, but the Aux fan works better there. Trans cooler actually has it's own SPAL fan and thermostat, so it's able to be mounted anywhere. It will actually get mounted under the vehicle, up above the underbody protection. Will make running lines to the transmission a breeze (very short in length).
Spent WAY too much time on the wiring harness (not really), but every connection is soldered/shrinked/taped, and the whole harness is loomed. I really hate shady wiring jobs, so I try to keep everything as OEM as possible. Well, I say that and then I notice my cheezy battery terminal fix! :giggle:
That part is only temporary until I figure something else out for it.
The hardware
Install pics
My H3 runs cool around town and if you're moving at all, but there are certain situations that cause the temps to climb quite a bit. Like sitting in a line of cars at a drive-thru at 5:30pm. Beating sun, black pavement, a/c blasting and other vehicles in close proximity really make for quite the heat load on the cooling system!
Friday afternoon I experienced just that. Ambient temp was 100f, vehicle was showing outside air temp as 110, intake temps were 140f (and that's WITH a snorkel...). Line was slowly moving forward, so I had just left the rig in Drive which means engine speed was at 625rpm. At that engine speed, the mechanical fan just doesn't move enough air to keep everything in check. Keep in mind, that I do have my H3 programmed to raise the idle to 850rpm when engine temps get above 200, but that's only with the transmission in park or neutral. When I moved the shifter to N, engine speed picked up and the mechanical fan brought the temps back down. But it's not always convenient to have to keep moving the shifter to keep temps in check.
Highest coolant temp that I saw while sitting in that line was 221f. Trans climbed up to 210, and engine oil temp remained about where it always does (225f). One very interesting thing to note, is that even with the actual engine temp at 221f, the "temp gauge" on the cluster was still showing just a hair under the half mark! Just something to keep in mind, as I frequently see people on here stating that "temp gauge never rose above half."
Anyway, in my opinion 220+ is too hot, so I decided to add a fan.
Simple way would be to just mount one up and put it on a switch or something. I wanted something better than that, so I went a little overboard.
Used a SPAL 12" Pusher (Their most powerful 12" model, straight paddle blades), and a PWM speed controller from a Chrysler (LOL). My factory PCM is able to output a PWM signal (for fan speed) based upon maps that reference engine coolant temp, A/C pressure, Trans Temp, Vehicle Speed..ect.
So basically, the computer controls the fan in the same manor as it would on a C6 corvette (same PCM). PCM reads sensors, references the maps, and then requests a fan % based on those maps. Aux fan ramps up slowly to the requested duty cycle (%). Aux fan speed only reaches what's needed to keep everything in check! Not running full blast all the time like it would be if on a toggle switch or something.
Here are some pics. You can see in the first pic that I had my trans cooler lined out for that space in front of my condenser, but the Aux fan works better there. Trans cooler actually has it's own SPAL fan and thermostat, so it's able to be mounted anywhere. It will actually get mounted under the vehicle, up above the underbody protection. Will make running lines to the transmission a breeze (very short in length).
Spent WAY too much time on the wiring harness (not really), but every connection is soldered/shrinked/taped, and the whole harness is loomed. I really hate shady wiring jobs, so I try to keep everything as OEM as possible. Well, I say that and then I notice my cheezy battery terminal fix! :giggle:
That part is only temporary until I figure something else out for it.
The hardware
Install pics
