2001 Chevrolet Silverado 5.3 4WD, Driver's Window Will Go Down, But Not Back Up

This 2001 Chevrolet Silverado LS 5.3 4WD came into the shop with a customer complaint that the driver's window would go down, but it would not go back up.

The first step was to confirm the customer's concern. When pressing the power window switch on the driver's door, we could hear clicking, but no upward movement. We discovered, as the customer said, that the window would indeed go down, but not up.

We pulled a wiring diagram and found the applicable circuits for the driver's side window motor. The green wire is the voltage supply wire with the ignition in the on or run position. Based on the clicking we heard earlier, we knew we had good voltage there. We double checked it for accuracy and it had constant voltage. The voltage was present with the switch not being activated and it was present continuously when the switch was being depressed to move the window down and up.

Below is a picture of the assembly, out of the door panel, showing the back of the switch with the wires.

This told us the supply circuit was good. We did the same checks on the black wire for the ground. It too checked good. We expected both of these findings, but wanted to perform a thorough diagnostic to be sure.

Next we checked the circuits for the up and down motion of the driver's window. The two wires that operate the driver's side window are the blue and brown wires. The two wires should show ground with key in the on or run position.

The blue wire (see below) should have battery voltage (B+) on it when rolling the window up and it should show ground when rolling the window down. The brown wire is the opposite: it should have voltage when rolling the window down and be grounded when rolling it up. (Basically, the two wires simply complete the circuit, one way or the other.)

The blue wire then could be thought of as the "Up" wire and the brown as the "Down" wire. In fact, this is how it is labeled in the schematic.

The blue wire should have voltage on it when the switch is depressed to send the window up and the brown wire should go to ground. The brown wire should have voltage on it when the switch is depressed to send the window down and the blue wire should go to ground.

The brown wire checked good for voltage when depressing the switch to roll down the window. The blue wire should have ground on it to complete the circuit: it did. Again, these findings were expected since the window would roll down with no problems.

Below is the blue wire showing ground when rolling the window down. This is good.

When we checked the circuitry for rolling the window up, we found the problem. The blue wire had voltage on it, as it should, when depressing the switch to roll the window up. However, the brown wire, which should be grounded in this case, to complete the circuit, was not grounded. Sometimes it showed no life at all (meaning it did not have voltage or ground); and other times, it showed to have constant voltage.

Below shows an instance when the brown wire showed no life at all, when trying to roll the window up. (Again, we rolling the window up, the brown wire should be grounded to complete the circuit.)

Below shows an instance when the brown wire showed voltage while trying to roll the window up. (Again, in order for the circuit to work, it must be grounded.)

This evidence told us that the motor and regulator were good. The problem was the switch. We replaced the Driver's Power Window Switch and the window went up and down as it should. (To replace the switch, there are two retainers that must be popped up and the assembly will lift out of the door panel. Then, on the back, there are two Torx bit fasteners, T-15s, to remove and the switch will come out of the assembly. To install, just reverse the steps.)

Below are a couple of pictures of the switch.

We tested it several times and then shipped the vehicle.

2006 GMC Sierra, 5.3, 4WD, Rear Brake Shoes (Single Spring Application)

This 2006 GMC Sierra 5.3, 4WD, came into the shop for its 100,000 mile maintenance. We replaced the spark plugs, wires and air cleaner element. We also added oil to the front and rear differentials.

Another service we performed was an all-around brake job. We replaced the front brake pads and the rear brake shoes. We also had the front rotors and rear drums resurfaced at a machine shop.

In this post, I will concentrate on the rear brake shoes. These have a single spring application. They are known to be a bit of a problem. Many techs and DIYers complain about this setup. I will show you a few things I have learned from doing them.

In the two pictures below, you will see the single spring. It looks something like a horseshoe and has a lot of pressure on it. They do make a special tool just for pulling this spring back and removing the brake shoes. I did not use the tool on this job. It is possible to do the job without the expense of the special tool. However, caution is advised, as the spring is very tight.

In the picture below, you will see one of the brake shoes. On this application, the whole apparatus is replaced. When you purchase the new brake shoes, it will come with the shoe and the parking brake lever attached. All of it comes off and is replaced, unlike on other applications where you simply remove a keeper and the parking brake lever remains on the vehicle. 

Removing the cable from inside the spring going to the parking brake lever can be troublesome. In the picture below, you will see the new brake shoe (parking brake lever and spring conduit attached). The parking brake cable goes through the spring conduit and hooks to the parking brake lever. Again, this is the part that many people find very frustrating.

To make this much easier here is what I do: first, (on this model with extended cab), I look below the back of the extended cab on the frame. In that area is the connector for the front cable coming from the parking brake to the two rear cables each going to one side respectively. Below you will see the area and then a picture of the connector on the frame:

Once the connector is located, I detach one (or you can do both at the same time) of the rear cables. See the picture below:

I can actually detach it just using my hands, so it is not that hard to do. I believe the top cable goes to the right (passenger) side and the bottom one goes to the left (driver) side. Once the rear cable is detached from the connector, I now have slack on the other end (the brake shoe end) to move the cable in and out easier. See the picture below:

There is a tab on the end of the spring conduit that must be pressed down to allow the cable to slip out of the spring. Sometimes the cable will come out of its own accord once I detach the connector. Now the brake shoe (with parking brake lever) will slide right off the parking brake cable. See the pictures below:

To remove the shoes themselves (without the special tool) I simply use a large screwdriver, pliers and a pair of side-cutters. There is an adjusting spring to remove, along with the adjuster.

I always grease the contact points to make for a nice, smooth and quiet braking experience. I use caliper grease on the rear brakes and front as well. See the picture below:

I also make sure to clean up all hardware with a good quality brake cleaner.

Once the job is done, I always torque the lug nuts to specification.

I torqued all four wheels to spec and then test drove the vehicle. All was well. The brakes felt good and smooth and the parking brake worked smoothly as well. We shipped this one to the customer. Another one fixed.

2000 Chevrolet Silverado Z71 1500 5.3, 4WD not engaging

This 2000 Silverado came into the shop with several issues.  The primary customer concern was the 4WD was inoperative.  A used transfer case had been installed in the vehicle within the past year.  The "Service 4WD" message was flashing in the Message Center in the dash. 

I started by hooking up the diagnostic machine and seeing what, if any codes were present. Sure enough a DTC (Diagnostic Trouble Code) C0323 was stored.  This code deals with a problem with the transfer case circuit.

Next, I checked the ATC 20 Amp fuse in the engine junction box.  This fuse is "Hot at all times".  It checked good.

Next step was to crawl under the truck, remove the transfer case shield, and have a look at the wiring and the connector.  I was going to check the orange wire on the circuit, which should have constant voltage on it to the Encoder Motor on the transfer case.  When I unplugged the connector though, I spotted a broken wire.  You can see the broken wire (tan wire) to the right of the downward hanging connector.



At this point, I soldered the wire back together and taped it up.  I cleaned some dirt from the connector body and applied some dielectrical grease to it.  After it was all back together, I started the truck, put it in neutral and tested the 4WD switch.  The truck would now engage 4WD just like it was suppose to.  I cleared the code and the truck's 4WD issue was repaired.