C5 Tech Corvette Tech/Performance: LS1 Corvette Technical Info, Internal Engine, External Engine, Tech Topics, Basic Tech, Maintenance, How to Remove & Replace
Sponsored by:
Sponsored by:

a/c fan speed control

Thread Tools
 
Search this Thread
 
Old Apr 9, 2011 | 11:43 PM
  #1  
99c5david's Avatar
99c5david
Thread Starter
Instructor
 
Joined: Apr 2011
Posts: 116
Likes: 0
From: Ponder Texas
Default a/c fan speed control

what controls the fan speeds on 99 FRC is it external or inside the a/c controller
Reply
Old Apr 10, 2011 | 09:54 AM
  #2  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

What HVAC controller do you have. duel Climate control or all manual? That makse a big difference!

BC
Reply
Old Apr 11, 2011 | 10:58 PM
  #3  
99c5david's Avatar
99c5david
Thread Starter
Instructor
 
Joined: Apr 2011
Posts: 116
Likes: 0
From: Ponder Texas
Default

manual i think three *****
Reply
Old Apr 12, 2011 | 01:08 AM
  #4  
PEERPSI's Avatar
PEERPSI
Pro
15 Year Member
All Eyes On Me
 
Joined: Aug 2010
Posts: 545
Likes: 4
From: Calgary Alberta
Default

Your speed selector or fan switch applys voltage to the motor through a series of 4 resistors for the first 4 positions. For the fifth or highest fan setting all the resistors are bypassed and a relay closes a set of contacts thereby appling voltage directly to the motor. As you move up from high to low through the first 4 positions one of the 4 series resistors is bypassed with each step.

There is also a blower motor relay that provides power to the system when the key is on. It is located on the multi use relay and fuse bracket, above the Body Control Module.

I believe the fan control module is located behind the LH side of the blower motor, under the RH side of the instrument panel.

PM an email address and I can send you a schematic.
Reply
Old Apr 12, 2011 | 01:58 AM
  #5  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

If you have a manual HVAC, here is what the controller looks like (literaly) Yours will be burnt just like this one if its bad:




It lives here:






Schematic:

Reply
Old Jun 27, 2011 | 11:56 AM
  #6  
Will94ZR1's Avatar
Will94ZR1
6th Gear
 
Joined: Jun 2011
Posts: 6
Likes: 0
From: magnolia texas
Default

i have a 94 lt1 with duel Climate control (all buttons) and my fan speed selector is not working it is actually stuck on auto can you help?
Reply
Old Jun 27, 2011 | 12:37 PM
  #7  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

Sorry bud,,, you need to jump over to the C4 TECH section.

C5 stuff is WORLDS DIFFERENT!
Reply
Old Jun 27, 2011 | 12:56 PM
  #8  
SaberD's Avatar
SaberD
Melting Slicks
10 Year Member
 
Joined: Nov 2008
Posts: 2,938
Likes: 65
From: Rochester Hills MI
Default

i had one of these go out in my 99 vette frc and my 99 grand am. i guess gm had a bad year for blower motor resistors.
Reply
Corvette Stories

The Best of Corvette for Corvette Enthusiasts

story-0

2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

 Michael S. Palmer
story-1

5 Best & 5 Worst Corvette Daily Drivers

 Joe Kucinski
story-2

The Headlights of Every Corvette Generation Explained

 Joe Kucinski
story-3

5 Best & 5 Most Overrated Corvette Track Packages of All Time!

 Joe Kucinski
story-4

Every 2027 Corvette Engine Explained

 Joe Kucinski
story-5

Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

 Verdad Gallardo
story-6

10 Ugly Corvettes That We Still Kinda Love

 Joe Kucinski
story-7

Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

 Brett Foote
story-8

10 Things Every Corvette Owner Needs (2026 Edition)

 Michael S. Palmer
story-9

8 Most "Only Corvette Owners Understand" Quirks and Problems

 Pouria Savadkouei
Old May 29, 2012 | 12:39 AM
  #9  
Jondamnit's Avatar
Jondamnit
Instructor
10 Year Member
 
Joined: Apr 2012
Posts: 104
Likes: 1
From: Vacaville California
Default Access and replacement..?

What is the best way to access the blower control module to replace it?
Reply
Old May 29, 2012 | 04:40 PM
  #10  
Bill Curlee's Avatar
Bill Curlee
Tech Contributor
Supporting Lifetime Gold
Veteran: Navy
25 Year Member
Liked
Community Favorite
 
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Default

Look up under the passengers side dash. Its right there on the underside of the air box. Just LOOSEN the rear screws as they are slotted.

If your BIG,, you can remove the passengers seat for more room.


BC
Reply
Old May 29, 2012 | 06:04 PM
  #11  
Jondamnit's Avatar
Jondamnit
Instructor
10 Year Member
 
Joined: Apr 2012
Posts: 104
Likes: 1
From: Vacaville California
Default Thanks...

First off, Thanks Bill for your service this day after Memorial Day... Second I'd like to thank you for all the posts and insight you supply here on the forums. I've solved my high ignition resistance issue, No vacuum from the manifold to the AC duct vents and fixed my floppy drivers side mirror all with the info you've supplied to the forums. Thanks! Owe you a beer if we ever cross paths...
Reply

Get notified of new replies

To a/c fan speed control





All times are GMT -4. The time now is 01:01 AM.

story-0
2027 Chevrolet Silverado 1500 First Look: Everything You NEED to Know!

Slideshow: Is the 2027 Chevrolet Silverado 1500 the best Silverado yet?

By Michael S. Palmer | 2026-06-16 08:01:12


VIEW MORE
story-1
5 Best & 5 Worst Corvette Daily Drivers

Slideshow: 5 best and 5 worst Corvette daily drivers

By Joe Kucinski | 2026-06-15 10:32:13


VIEW MORE
story-2
The Headlights of Every Corvette Generation Explained

Slideshow: The headlights of every Corvette generation explained

By Joe Kucinski | 2026-06-15 10:17:14


VIEW MORE
story-3
5 Best & 5 Most Overrated Corvette Track Packages of All Time!

Slideshow: The 5 best and 5 most overrated Corvette track packages ever.

By Joe Kucinski | 2026-06-09 12:46:45


VIEW MORE
story-4
Every 2027 Corvette Engine Explained

Slideshow: Every 2027 Corvette engine explained

By Joe Kucinski | 2026-06-09 12:16:31


VIEW MORE
story-5
Designer Imagines A Corvette That Looks More Like a Corvette Than the Corvette

Slideshow: A Jaguar designer's personal project imagines what a modern front-engined Corvette might look like if Chevrolet revisited the golden age of the Stingray.

By Verdad Gallardo | 2026-06-08 19:53:43


VIEW MORE
story-6
10 Ugly Corvettes That We Still Kinda Love

Slideshow: 10 ugly Corvettes that we still kinda love.

By Joe Kucinski | 2026-06-03 10:34:17


VIEW MORE
story-7
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer

A lot of money has changed hands at the online auction house over the years.

By Brett Foote | 2026-06-03 10:21:50


VIEW MORE
story-8
10 Things Every Corvette Owner Needs (2026 Edition)

Slideshow: 10 great gifts Corvette enthusiasts actually want for Father's Day!

By Michael S. Palmer | 2026-06-03 15:43:40


VIEW MORE
story-9
8 Most "Only Corvette Owners Understand" Quirks and Problems

Slideshow: These are the quirks, annoyances, and oddly lovable problems that every Corvette owner eventually learns to live with.

By Pouria Savadkouei | 2026-05-28 09:31:39


VIEW MORE