Conversions & Swaps LSX Engines in Non-LSX Vehicles
Sponsored by:
Sponsored by:

ECM A/C controls, whats what?

Thread Tools
 
Search this Thread
 
Old Sep 29, 2008 | 02:39 PM
  #1  
1BadAction's Avatar
Thread Starter
TECH Fanatic
iTrader: (10)
 
Joined: Aug 2004
Posts: 1,030
Likes: 0
From: Dallas, TX!
Default ECM A/C controls, whats what?

ok, as far as I can find, there are 5 different pins in the ECM red plug(99 silverado) that relate to the a/c.

11 Recirc Sw DK BLU (to 2 pin connector on passenger side of harness) (A/C high press)

17 AC REQUEST DK GRN/WHT

33 Recirc Door DK GRN

43 A/C CLU DK GRN/WHT

55 CYC SW in DK GRN (A/C system)

I'm pretty sure 11 and 43 go to the compressor, and 17 and 55 go to the A/C head unit, that leaves 33. what is it for? are my locations right? any guidance is appreciated. thanks.

Last edited by 1BadAction; Sep 29, 2008 at 02:44 PM.
Reply
Old Sep 29, 2008 | 02:51 PM
  #2  
bczee's Avatar
TECH Senior Member
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (12)
 
Joined: Jan 2006
Posts: 6,670
Likes: 6
From: Concord, CA
Default

In the HAVC box under the dash.. In general, there is a few doors to direct the air (heated or cooled) to the correct outs, there is also a door to either let the air in from the outside vent or to be recirculated from the inside air (some call this setting MAX). The PCM or BCM can control this or some old cars have manual controls that would operate the doors by vacuum or elecrical control on the door.
Reply
Old Sep 29, 2008 | 02:56 PM
  #3  
1BadAction's Avatar
Thread Starter
TECH Fanatic
iTrader: (10)
 
Joined: Aug 2004
Posts: 1,030
Likes: 0
From: Dallas, TX!
Default

ok... I didnt know that the PCM actually had "control" of the recirculation in the newer vehicles. In my 93 the electronic control handles that.
Reply
Old Sep 30, 2008 | 01:28 AM
  #4  
bczee's Avatar
TECH Senior Member
20 Year Member
Photogenic
Photoriffic
Shutterbug
iTrader: (12)
 
Joined: Jan 2006
Posts: 6,670
Likes: 6
From: Concord, CA
Default

As I said, I was not sure if the PCM or BCM did. I am sure someone else would know for sure.. I am using my stock OEM Chevelle HVAC and controls.. so I didn't research that far into the pin and other harness cause I didn't need too.
Reply




All times are GMT -5. The time now is 11:40 PM.

story-0
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin

Slideshow: This heavily modified 1971 Camaro mixes classic muscle car styling with a fifth-generation Camaro interior and modern LS3 power.

By Verdad Gallardo | 2026-05-12 18:06:42


VIEW MORE
story-1
6 Common C5 Corvette Failures and What's Involved In Repairing Them

Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.

By Pouria Savadkouei | 2026-05-07 18:44:57


VIEW MORE
story-2
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph

Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.

By Verdad Gallardo | 2026-04-21 13:57:02


VIEW MORE
story-3
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked

Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...

By Pouria Savadkouei | 2026-04-16 10:05:15


VIEW MORE
story-4
Top 10 Most Powerful Chevy Trucks Ever Made!

Slideshow: Top ten most powerful Chevy trucks ever made

By | 2026-03-25 09:22:26


VIEW MORE
story-5
Hennessey's New Supercharged Silverado ZR2 Has 700 HP

Slideshow: Hennessey has turned the Silverado ZR2 into a 700-hp off-road monster with supercharged V8 power and a limited production run.

By Verdad Gallardo | 2026-03-24 18:57:52


VIEW MORE
story-6
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes

Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.

By Verdad Gallardo | 2026-03-23 18:53:41


VIEW MORE
story-7
Awesome K5 Blazer Restomod Comes With C7 Corvette Power

Slideshow: A heavily reworked 1972 K5 Blazer swaps its off-road roots for a low-slung street-focused build with modern V8 power.

By Verdad Gallardo | 2026-03-09 18:08:45


VIEW MORE
story-8
10 Camaros You Should Never Buy

Slideshow: There are thousands of used Camaros on the market but we think you should avoid these 10

By | 2026-02-17 17:09:30


VIEW MORE
story-9
10 LS Engine Myths That Refuse to Die

Slideshows: Which one of these myths do you believe?

By Verdad Gallardo | 2026-01-28 18:10:11


VIEW MORE