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.

2004 Ford Crown Victoria LX, 4.6, AC Not Blowing Correctly (Air Blowing Erratically)

***This is not the actual vehicle. This picture can be found here: http://photos4.automanager.com/022534/912caaf73c96ba49b30cbfdde96d29fb/666df77415_640.jpg.***

We had a 2004 Ford Crown Victoria LX with a 4.6 come into the shop with a customer concern of the AC not blowing correctly. Upon further investigation, we found the AC, when in the Norm AC or Automatic AC position, would sometimes blow the air out of the defrost and floor, instead of the vents.

Additionally, when driving the vehicle, at about 45 MPH, the air would switch from the vents to defrost/floor and then, once you decelerated, back to vents. Once it switched back, it seemed to stay there.

After checking the OE info, I checked several components and hoses to make sure everything was okay. Everything under the hood checked good. 

I then turned my focus to the passenger compartment. I never follow the OE "diag tree" for these, because I find there are a lot of unnecessary steps to it. 

The first thing I did, was disconnect the vacuum connector under the passenger's dash to make sure vacuum was there (sorry no picture of this). It was. I next went to the Climate Control Module in the dash.

I removed the four fasteners holding it in place, so I could pull it out and look at the back side of it.

 Below is the unit removed from its mounting spot. (Notice the different colored vacuum lines going to the unit.)

I then disconnected the vacuum connector on the rear of the CCM (Climate Control Module). There are two fastener nuts to remove to be able to do this.

Here is a look at the vacuum connector:

Next, I connected a handheld vacuum pump to the port with the black plastic line. The black plastic line is the source vacuum for this unit (it comes from the intake manifold). I wanted to be sure we had source vacuum to the unit before going any further. See picture below for the hookup:

The other vacuum lines go to various HVAC doors. The blue, for instance, goes to the door controlling air flow to the vents. Three of these can be seen through the hole where the CCM was removed.

You can see in the above pic three of the lines: the blue, the red and, just to the bottom (on the same one the red is connected to) is the yellow. 

Now, I was ready to once again drive it down the road. This time I had the vacuum pump/gauge installed to keep an eye on the vacuum as we hit our 45 MPH mark.

Below is a picture of the gauge reading our source vacuum, which was good, steady and constant at all times (at idle and any MPH/load): this told us, there was no issue with it. 

You can see from above, it was reading about 17 inHg. This is more than enough vacuum: so again, this checked out good.

We then moved to the port with the blue vacuum line (for the vents). As we drove down the road, we kept a close eye on the gauge. As we hit 45 MPH the vacuum dropped significantly (it should hold steady at all times). See the pic below:

Below is yet another picture, this time the vacuum is a bit more, but still significantly low:

This verified an issue with the CCM. There is a vacuum unit internal to the CCM which is designed to hold the source vacuum. It was failing. We opted to replace the CCM. 

In the picture below, you can see the vacuum holding (on the port with the blue line: the one going to the vents) as it should.

We put it all back together and drove it several more times. Each time it worked as designed. We made sure all the controls on the new CCM functioned properly and shipped it.

2003 Dodge Caravan SE 3.5 Engine, Noise in Engine Compartment (Especially at Idle)

***This is not the actual vehicle that was in our shop. This is an image of a similar model. It can be found at http://www.autodetective.com/_upload/photos/dodge/grand%20caravan/2003/29051.jpg.***

We had a 2003 Dodge Caravan SE 3.5 come into the shop. The customer concern was a noise under the hood. The noise was more noticeable at idle. When the RPM's were increased the noise all but went away.

We used a stethoscope in an attempt to isolate the noise. At first we suspected the catalytic converter, but it was quiet. We then listened at the right side (rear, transverse engine) exhaust manifold. It too was quiet.

When we listened to the cross-pipe (over the transmission) and the left (front) exhaust manifold we heard the noise plainly.

We decided to remove the starter to inspect it, having had some issues in the past with starters causing noises like this one. The starter however checked out good. We took a look at the flywheel (flex plate), inspecting the teeth for any wear or issues; again, all was good.

We decided to remove the inspection plate on the bottom of the bell-housing to get a better look.

When we did this, we spotted the problem.

In the pictures below, you can see the issue. (The pictures are of the same torque converter bolt.)

 



The problem was the torque converter bolts (4 on this model) had become loose, allowing the torque converter movement.

On all the vehicles I have worked on, I had never seen this before. I called the customer to see if there was some repair history we had not been privy to.

Sure enough, the customer told me that within the past year a shop had the transmission out of the vehicle for a repair. Evidently, they did not tighten the converter bolts back tightly.

We applied some thread sealant to the bolts and tightened all four up. Yes, all four were loose. The one in the above picture was the worse of the four though.

We put the starter back on and everything back in place and started the engine. Everything was now nice and quiet.

1998 Ford Explorer XLT 4.0, 2WD, Temperature Hand in Dash Inoperative

This 1998 Ford Explorer XLT 4.0, 2WD, came into the shop for a No Crank Concern. Once we found the issue there (a faulty Drive Belt Tensioner not allowing the Alternator to charge), we let the vehicle run to check the charge and the new battery we had installed.

As we let the vehicle run, we noticed the temperature hand in the dash was inoperative. The vehicle had reached normal operating temperature (after running for several minutes) but the hand was still below the "C" on the Temp gauge in the dash.

Below is a picture of the inoperative temp hand with the vehicle at normal operating temperature. The hand has obviously not moved and thus is inoperative for some reason.

The customer wanted us to find and fix the problem.

First, we needed to do some testing to see if it was the gauge in the dash that was faulty, the circuitry or the sensor under the hood. In order to see which it was, we had to disconnect the temp sensor. It is located in the thermostat housing (black plastic assembly).

With it unplugged, I jumped the the circuit to Battery (-). In the picture below you can see my jumper wire connected at the negative battery post on the battery.

Next, I put a probe gently into the connector for the temp sensor, so as to jump the circuit. If the circuitry (the wiring) from the connector to the gauge was good . . . and, if the gauge in the dash itself was good, this test would prove that because the hand in the dash should move all the way to the "H" position or even a little past.

In the next pic is a shot of the probe placed gently in the connector and the jumper wire connected to it.

The word gently is important here. The probe should never be forced or jammed into the connector. This could ruin that terminal of the connector.

Now, with the circuit jumped, we looked at the dash to see if the hand had moved or not. Below you will see the evidence.

Now we saw that the temp hand had moved all the way past the "H" mark on the gauge. This told us two valuable things: first, the circuitry (wiring) from the temp sensor connector all the way to the gauge was good; and second, the gauge in the dash was also good.

This one simple test ruled out two of the three possibilities and left us with the conclusion that the temp sensor was faulty and needed replacing. After replacing the sensor (we actually had to replace the entire t-stat housing because the sensor could not be removed from the housing: the boss (threads) had come loose and was turning with the sensor. I have another post about replacing the t-stat housing on a Mustang) the gauge in the dash now worked as it was designed to do.

We filled the coolant system up with coolant and gave it a test drive.

In the picture below is the temp hand operating normally with the vehicle running at normal operating temperature.

Another job was completed and we shipped the vehicle. The test was quick and easy and saved us a lot of time from guessing at what "might be" wrong to find what "definitely" was wrong. This is why the old adage says, Test . . . don't guess!

2001 Nissan Xterra 3.3 2WD, Noise When AC is On (Fan in Dash Making a Noise)

This 2001 Nissan Xterra 3.3, 2WD, came into the shop for an oil service and a customer concern of noise when she would turn on her AC.

Verifying the concern, we could hear the blower motor making noise as it ran at all speeds. We set out to remove the motor to find out what was causing the noise. We suspected napkins or papers from the glove box.

First, we opened the glove box and removed the contents. On this model, to gain access to the blower motor you must remove the glove box. There are 6 Phillips screws that hold the glove box in place.

Remove these six screws.

Once the 6 screws/fasteners are removed, the blower motor is in plain view.

Next, we removed the 3 screws/fasteners that hold the blower motor in place.

When we removed the blower motor, here is what we found inside the fan assembly. I would say this would cause a bit of noise!

And, another view.

We made sure there was no more debris/trash in the housing where the fan sits. Below is a view of this chamber from the bottom looking up.

And another view of the same, from a slightly different angle and with the flash turned on, so it's easier to see.

Once that was done, we re-installed the blower motor. We then tested it to make surer it was quiet and it was. (We also went ahead and replaced the two cabin air filters while we were in the space, but we did not take photos of that procedure.)

We got it all back together and the fan now runs quietly on all speeds.

1989 Ford Ranger XLT, 2.9, Brake Lights Inoperative

We had this 1989 Ford Ranger XLT with a 2.9 engine come into the shop with a customer concern of no brake lights.

I decided to start my diagnostic at the stoplight switch. I could have started at the fuse, but if I have voltage at the switch my fuse is good. (I already knew the bulbs were good, we had replaced one, so I wasn't worried about them.)

When I checked the stoplight switch without the brake pedal depressed, I found voltage on one wire and ground on the other. This is normal and what we would expect to see. Below, you can see me testing the two circuits with a PowerProbe.

First, the circuit with voltage. (Notice the red light illuminated in the top right of the Probe and the reading on the face at 12.6 v.)

Next, the ground circuit. (Notice the green light on the top left of the Probe illuminated, along with the reading of 0.0 v.)

So far, so good. This is as it should be. Again, this shows my fuse to be good (because we have voltage) and we have a good ground circuit as well). So, at this point, I am not concerned about my fuse or the wiring from the fuse to the switch, all that is good.

The next step in the diagnostic is to load the circuit by depressing the brake pedal. When this is done the switch should activate and allow voltage to flow. So then, when testing it with the Probe, we should see voltage on both circuits.

However, when we depressed the pedal (applied the brakes) the circuits remained the same as above: that is, one circuit showed voltage and the other still showed ground.

Below you can see that the brake light is not illuminated.

When I unplugged the switch and applied voltage to the ground circuit, the brake lights illuminated.

This proved that the stoplight switch was faulty and needed replacing.

After I replaced the switch, I once again depressed the pedal, unlike before, now both circuits showed voltage.

Below is the first circuit, clearly showing voltage.

Next, is the second circuit, which before had remained ground, but now shows voltage (as it should when the switch is working properly). (Sorry it is a bit blurry.)

Now, with the switch working properly, the brake lights were illuminated.

We put everything back together and another job was done!

2006 Nissan Pathfinder SE 4.0 RWD with a Oil Pressure Gauge Reading High All the Time

This 2006 Nissan Pathfinder SE (145,143 mi.) with a 4.0 and RWD came into the shop with a customer complaint that the oil pressure gauge had, over the course of a day or so, pegged out on "H" (i.e. High) and would not move or fluctuate.

First things first, we confirmed the level and condition of the oil and filter. Everything was good there. Next we confirmed the complaint. As soon as the vehicle was started, the oil pressure gauge hand went straight to the "H" and did not move. See the picture below:

The quickest check for this problem is to go underneath the vehicle and unplug the oil pressure sensor/switch. It is located on the right side (i.e. passenger side) of the engine, toward the front on the oil pan. We unplugged the sensor and then restarted the vehicle to see what would happen. Below is a picture of the sensor unplugged.

When we did this the oil pressure gauge stayed at "L" (i.e. "Low") and did not move at all. The red oil warning light also illuminated, as it should. Below is a picture of the dash with the vehicle running and the sensor unplugged.

With the sensor unplugged and the vehicle running, the gauge should bottom out at (or below) the "L". This proves that the circuitry is good and the dash is not the issue. With this response, it was obvious the sensor itself was the culprit.

We replaced the oil pressure sensor, reconnected the pigtail and started the vehicle. Now, the gauge read properly, showing good oil pressure.

This repaired the customer's issue and another one was out the door.

2005 Ford F150 5.4, No Crank/No Start

***This post will be a short write-up as FYI. It will not be as detailed as most posts.***

This vehicle, 05' Ford F150 5.4, came into the shop with a customer concern of a no crank/no start condition. Let me first give you the details of the complaint history.

The customer stated he had driven the truck as he normally does and parked it in the garage. The truck sat in the garage for a day or two. When he went out the next time to drive it, the truck would not crank over. When he would turn the key to the start position nothing would happen. He checked the battery and it was good.

He and a friend checked out a few fuses and a few other things but could not find the problem.

He called me and had the vehicle hauled to the shop.

When the truck arrived at my shop the battery was down (from the customer trying to start it numerous times); so, first things first, I replaced the battery. It was time to perform some diagnostic tests on this vehicle.

Next, I had an assistant turn the key to the start position and probed the wires at the starter solenoid. I found there was no voltage to the starter solenoid, it had ground all the time.

I then pulled a wiring diagram and checked the pertinent fuses for the starting circuit. All tested good. Next, I used a relay tester and checked the circuitry at the starter relay. I noticed the contacts that normally should show a ground when the key is not in the start position, were showing nothing at all.

The fuses and relays are located behind the kick panel on the right (passenger) side. See the picture below:

Next, I checked the fuses for the PCM and all were good. I had tried communicating with it with my scan tool, but had received an error message for "No Communication".

I then tested the PCM relay and found the problem. The PCM relay was not working. It had power to the relay, but the relay was not internally switching. I bench tested the relay and the first couple of times it tested faulty. I tapped it lightly a few times and it came to life.

In the pictures below is the relay:

I replaced the relay with a new one.

In the pictures below you will see where the relay is located in panel. (It is number 203 on the cover legend.)

Viola, the truck then cranked over and started right up!