This 2003 Chevrolet Silverado came in with the complaint that the blower did not work on any speed. The ABS and Brake lights were on as well.
Testing begins at the HVAC fuses in the driver’s side fuse box that is located behind the dash end cap.
The fuses need to be checked with the ignition switch on. The 10 amp fuse is listed as HVAC 1. The 30 amp fuse is listed as HTR A/C. There was no power on either fuse.
Time to go to the ignition switch for more testing. Although you can jump to just separating the steering column cover. I find it much easier to remove the instrument cluster trim panel first.
Then the knee bolster or under dash cover.
Next a well placed screw driver and a little twisting and the tilt lever pops out.
The lower cover is now removed and I am checking for power on the orange wire. I was not expecting power here. Since there is power on the orange wire with the ignition on, the ignition switch is not the problem. This is why it pays to test before replacing parts. If there would have been no power at the orange wire with the ignition on and the engine cranked and ran normally, then the ignition switch would have been faulty.
It took a little bit of searching to find where the orange wire enters the rear of the driver’s side fuse box. I had to move the rest of the wires around to find the orange wire.
It was a little bit more difficult because the wire color had changed to brown. That made it slightly more difficult to find. The color change however was a clear indicator of heat damage.
The damaged wire and terminal are located in the top left in the picture below.
There is a blue secondary locking pin that had to be removed before the terminal could be properly removed. I used a small pocket screwdriver to remove the secondary lock.
Another tool to lift the locking tab from the terminal.
The orange wire removed from the connector body.
Before cutting the wire I moved back to where the wire color was consistently orange. I did this so that I would be clear of any heat damage to the wire or insulation.
I made up a new wire and terminal and crimped it into place. I used heat shrink tubing to insulate the connection.
I installed the wire back into the connector body and secured it with the blue secondary locking tab.
I used a mirror and flashlight to inspect the rear of the fuse box for damage. I could see signs of some melted plastic.
I loosened the 7 mm headed bolt that attaches the main harness to the rear of the fuse box.
There are a couple of latches that have to be released to remove the fuse box from it’s mounting bracket. You can see one of the latches above my thumb in the next picture.
With the fuse box fully removed form the truck I could inspect the terminals for damage. The damage to the fuse box was very minor and since one was not readily available, the customer and I decided to clean the terminal and reuse the fuse box.
To clean the terminal, I cut a slice off of an eraser and checked to make sure it would fit in between the terminals.
I then used my pocket screwdriver to support the eraser while I cleaned the terminal.
After installing the fuse box and repairing the harness, power is present at the fuses and the blower is back working.
A close examination of the damaged terminal and wires showed that the heat radiated out from the crimp. The terminal where it contacts the fuse box terminal was only very slightly heated.
The terminal where it contacts the fuse box terminal was only very slightly heated. This is why the fuse box was reused without any problem. If the center of the heat had been at the actual contact points between the male and female terminals, a new fuse box would have been needed to properly repair the condition.
This is a new wrinkle in ongoing blower failures on these trucks.
For more of the common problems with the HVAC systems on GM trucks click here.
I am assuming that you are checking the connector at the blower speed controller. If there is power on the black wire then that should be your problem. It should have a ground signal at all times. The ground termination point is supposed to be at the driver’s side firewall, under the hood near the cruise control servo/module.
…please ignore above posting on no power at 30amp HVAC fuse…I don’t think my tester had good ground when checking…I do have power.
I still however have no heat. there is power coming out of all three wires…black (when tested to ground), purple (when tested to ground) and brown (when tested to positive). They are hot at all times. I’ve jumped the blower motor fan to the battery it it runs fine.
Bottom line is that on this 2000 jimmy, no heat, blower at any speed, no a/c, pushing the a/c and rear defogger buttons on selector does nothing…indicators do not light up. This is a automatic computer control module, not the less expensive version with the resistor. Thanks!
Hi…I have almost the same problem. I have power in the fuse at the dash fuse panel for my HVAC (2000 jimmy) but not at the 30amp fuse for the HVAC in the engine compartment fuse panel?? Thank you!
If there is no power on the orange wire at the ignition switch with the key on, the engine will start and run with no other problems, the ignition switch (electrical portion) is faulty. You will find more information at the article address. You will need to copy and paste the address.
http://www.sparkys-answers.com/2010/11/2003-chevrolet-trailblazer-blower-not.html
This is exact same problem I am having on the same type truck. Several steps in you stated you checked power in the orange wire and found it. This is where mine differs, no power in orange wire. I traced it back to steering column and it attachs to block below the ignition switch. Would the ignition cyliner be bad or is it some type of switch? Thanks