Fan control with AC and 05 fans on DBC truck
03-19-2016, 06:30 PM
#23
How? What pins did you use? I don't remember how mine is wired, I do remember that I had to use the A/C clutch power wire for high speed, but the way I have my relays powered the PCM only gives low speed by engine temp. With dual SPAL 16" fans it has never overhet, but I would like the PCM to bring on high speed for engine cooling if needed.
Your work is not done yet young man, now you have to draw a circuit diagram for me.
Your work is not done yet young man, now you have to draw a circuit diagram for me.
03-19-2016, 07:28 PM
#24
You can do it 2 speed without the AC pressure sensor and reacting to AC engagement, but as mentioned you will only have High when the AC is on so the PCM will only control Low. I have mine so the computer controls High and Low and will power on High with the AC. Advantage being you now have two ranges for temp control instead of just 1 and it reacts to the AC clutch.
I put the relays under the fuse box, and just used D3 (dark green/white) for the activation wire (see GM diagram in the post above).
Heres what it all looked like:
I put the relays under the fuse box, and just used D3 (dark green/white) for the activation wire (see GM diagram in the post above).
Heres what it all looked like:
Last edited by Atomic; 03-19-2016 at 08:19 PM.
03-19-2016, 07:59 PM
#30
Do elaborate...the fans can do high/low speed based off of ECT, and AC pressure IF you have a ac pressure sensor and an 02+ computer. If there is no sensor there is nothing to tell it to turn on high. The picture above is the OEM harness. I would believe you if you said you have an AC pressure sensor.
Last edited by Atomic; 03-19-2016 at 08:19 PM.