Alpha-N, Turn On the Fans.

[Nickelin'Dimer]

I've got a '99 Sonoma w/LN2 (2200) auto & A/C. I'm looking to do the Taurus 2-spd fan install, and would like to use the PCM to control it... if possible. Is it possible? And if so, how? I'll understand if it can't handle two separate fan circuits, so I'll just design the control differently if need be. But I do want to have PCM control over at-least one of the circuits, so how's it done?

[misnblu]

Nickel, that shouldn't be too hard using the PCM to control the circuits.
If anything, you'll need to run a relay to provide power to the fans once the circuit is energized by the PCM for their fan circuits.
So you'd program your HPT for your fans just like you'd do on your stock fans with the exception that the control would be through the relay to your new Taurus fans.
Maybe this sounds too simple but it's feasible and would think that it would work.
Good luck man.

[Nickelin'Dimer]

You're right... It does sound too simple. First off, there isn't a factory electric fan! The whole idea of using the taurus 2-spd is to do-away with the power-sapping mechanical thermo-clutch job the factory installed. Secondly, I want the speeds to activate under the conditions as follows:

A/C off, coolant temp "on" setting: Low speed

A/C on, coolant temp "on" setting: Low & High speed

A/C on, coolant temp not at "on" setting: High speed.

I know I'll hafta use relays (75A from what I hear), but can I control the two speeds separately with just the PCM? That's what I wonder...

[HawkZ28]

It may be a deal like with the TB's. You can program the fans to come on, but only in a 2006 (?) and later model/PCM.

Not sure on your PCM, but if you have the fuse holder populated, and you get power to it after turning on the fans w/ the scanner or tune, it should work.

I have the same problem on my Collie- I'm just running a Flexalite controller, with no problems. Maybe 1 more wire to hook up vs doing it the way that you/I'd like to. I don't have a fuse for it that's populated, though. I don't know how different your block is from my 96 Blazer that I used to have.

[Nickelin'Dimer]

Is DMP around here somewhere? I'll bet he can tell us how he wired his Taurus 2-spd.

[csxtreme]

I plan on doing this myself when I get around to it.
gm uses 3 relays on their two fan systems.
the grand am, alero, malibu, 4cyl use the same computer part number as the s10 and have dual fans.
using their wiring diagram and pin outs should give dual or dual speed fan control.
I printed out the diagram from work a while back but no clue where it is now...

[Nickelin'Dimer]

Please be sure to share it when you do find it! It's summer already & having to run the A/C (For a friend with allergies) with the mech fan causes the needle to rise above 210. And I don't feel safe doing that while running 87-octane.

[csxtreme]

might consider a 180 t stat and larger core radiator.
the mechanical fan moves a ton of air

[Nickelin'Dimer]

Truth told, fully wiring-in the Taurus 2-spd is allot more affordable for me. Plus... I don't have a credit-card, so anything I need must be bought locally. And I have yet to find a replacement thermostat for my truck at any parts-store that's rated at less than 195*.

[Nickelin'Dimer]

IIRC, I have a Chilton's that covers the W-bodies. I'll look for it & try to get-back to you on the wiring.

P.S.: Don't expect pictures, as I don't have a scanner.