No.

Everything is pcm controlled

 

Without a pressure sensor? Do your fans come on high with A/C or just low?

 

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.

 

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:

 

That is what I am asking about. What wires control high and low by ECT?

 

Not true. My high speed is pcm controlled by ECT, as is the low speed.

 

How do you do it?

 

OEM efan harness

 

On a 2000 truck?

 

See this factory harness diagram:

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.