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!

2004 Acura TSX 2.4 Engine, Right Rear Door Actuator Replacement

(***This is not a picture of the actual vehicle we worked on. This is a picture of a similar vehicle, a 2004 Acura TSX. This picture is found at: http://images.dealerrevs.com/pictures/64200518.jpg.)

We had a 2004 Acura TSX with a 2.4 engine come into the shop with a customer complaint of inoperative door locks. We were told the vehicle had been purchased from the original owner. The original owner said the door locks all stopped working at the same time.

The customer had already had a couple of parts replaced on the vehicle to try and solve the problem, but the original complaint persisted.

First, we confirmed the customer complaint. We discovered that the LF (i.e. driver's front door) door lock worked properly. It would lock and unlock both with the key in the door and with the switch. (The customer had told us the remote had not worked in a long time, so it was not part of the equation.)

We also noticed the LR (i.e. driver's rear door) would lock intermittently, but would never unlock. We pulled the wiring diagram and tested through the schematic. The fuses all checked good and the circuits were working properly. When we would operate the locks, you could feel the door locks trying to lock and unlock.

We concluded the culprits causing the problem were the individual door lock actuators on the LR, RF and RR doors. The LF worked perfectly.

In this article we will show you the steps to replace the RR door lock actuator. We replaced all three (LR, RF and RR), but will only show the one. The LR is identical and the RF is similar, though there are some slight differences.

In the picture below, you will see the RR door. At this point, nothing has been disassembled.

There is no particular order to follow with some of the removal process, this is just how I choose to do it. First, remove the inside door handle cover. There is a small tab that needs to be depressed and then the cover will pull out. I used a pocket screwdriver to depress the tab.

Next, remove the two fasteners (screws) behind the cover.

Next, I removed the door window switch. I used a pocket screwdriver to leverage under the plastic and popped it up to remove it from the door handle.

Depress the tab to disconnect the wiring harness from the door window switch.

Next, remove the plastic cover on the door handle. Be careful as not to break the plastic tabs on the cover. Again, the pocket screwdriver was utilized to pop it off.

Once it is removed, two bolts can be seen that need to be removed. They are Phillips headed fasteners.

Here is a closer look at the bottom fastener.

Here is a closer look at the upper fastener. Remove each with a Phillips screwdriver.

Next use a tool to pop the door panel keepers away from the door.

Once the door panel is loose, the door handle cable must be detached. There is a plastic keeper that must be pushed back to allow the cable to come out of the inside door handle assembly.

Below, the cable is visible once it has been detached from the inside door handle assembly. At this point, the door panel can be removed from the door and set aside.

Here is a look at the inside of the door with the panel removed.

The plastic must be partially removed (peeled back) to access the door lock actuator assembly. First, use a tool to remove the plastic keeper at the top right corner.

Next, peel the plastic back out of the way.

With the plastic pulled back out of the way, the door lock actuator assembly can be seen. Here the two electrical connectors are visible. These must be unplugged.

Below are the two connectors unplugged from the door lock actuator assembly.

The next shot is a bit tough, but inside the door, there is a rod that must be disconnected from the door lock actuator assembly. It is the outer door handle rod. Like the one before (i.e. the inside door handle cable) there is a plastic keeper that must be pushed back to allow the rod to be removed from the assembly. This keeper was brown and is visible in the picture below.

Once the outer door handle rod has been disconnected, the three fasteners (again Phillips) must be removed. These three fasteners are the main ones holding the door lock actuator in place. Be careful! These can be tough to get out and you do not want to strip the heads. If you do, you will have to pull out the drill!

Once the three fasteners have been removed, pop the inside door handle cable keeper off the door.

The door lock actuator assembly will now drop down and pull out of the door.

To remove the actuator itself from the assembly, remove the screw holding the plastic cover.

There are a couple of tabs to depress to allow the plastic cover to be pulled back out of the way, so that the door lock actuator is visible.

Remove the screw holding the actuator in place and gently lift the actuator away from the assembly.

To reassemble, just reverse the preceding steps. Once everything is reassembled and the wiring harnesses and door cables and rods are reattached, always test their operation before finishing the job. Make sure the door locks work properly, both locking and unlocking. Make sure the outer and inner door handles will open the door. Make sure the window switch operates the window up and down.

Make sure to leave a clean work area. Use cleaner if necessary to clean the door panel, window and outside of the door.

Once we were done, we tested everything and all was a go. The door locks on all doors now worked properly and normally.

With that, we shipped the vehicle. Another job done.

2004 Chevrolet Silverado 4.3, Left Side Marker/Turn Signal Bulb Replacement

(This is not a picture of the actual vehicle we worked on. This is a similar vehicle, a 2004 Silverado. The picture is from: http://www.edmunds.com/chevrolet/silverado-1500/2004/?sub=regular-cab.)

We did an oil service on a 2004 Chevrolet Silverado 4.3. As part of an oil service, we always do a safety inspection on the vehicle. The safety inspection consists of checking things like tire pressure, belts and hoses and the external lights, among other things.

As we checked this one, we found the left side marker/turn signal bulb was not lighting. Many have questions about how to change certain bulbs on vehicles. Some are easier than others. Here is how you change this one. 

First, we had to remove the headlamp assembly. To do this, we had to remove the holding pin. It simply slides out.

Once the pin is removed, the headlamp can be lifted up and moved out of the way. We did not disconnect the headlamp, we just simply moved it aside to gain access to the lower assembly.

Now that the headlamp assembly is moved, we can get to the lower assembly. There is a plastic tab that moved be pressed to snap the assembly out of the bracket, allowing it to be moved to get to the bulb. In the picture below, I am pointing to this plastic tab with my screwdriver.

Once the tab is pressed, gently pull forward on the assembly. Be careful as this is done, so as not to break the plastic tabs. The picture below shows the assembly moved out from the bracket.

Below is another picture of me pointing to this plastic tab, this time with the assembly removed. This gives a better view of the tab.

At this point, it is a matter of replacing the burnt bulb. A simple twist of the connector will free it from the housing, then pull the old bulb out and replace it with a new one. The next picture shows the bulb now illuminated.

We then put the connector back into the housing and snapped the assembly back in place.

When reinstalling the headlamp assembly, you must get the plastic tabs/line up pins in the proper slots. The picture below shows the two tabs on the bottom of the headlamp assembly.

Those two tabs go into two slots. The picture below shows the two slots.

Once these are lined up properly, the headlamp assembly will go back in place and the holding pin can be slid back into place.

Once everything was back together, we did a quick recheck to make sure the bulb was illuminating properly.