In my opinion, this is a serious engineering blunder. I can only assume that the intentions of making this very important linkage hinge out of plastic was to save a couple dollars on the assembly line. But is a couple dollars worth risking the safety drivers? Luckily, we at www.autopartsdirecttoyou.com have a solution. We carry a replacement wiper transmission which has METAL hinges, like they should have been from the factory. This replacement part has a lifetime warranty and is guaranteed to never fail on you. The replacement of this part is not extremely difficult and is achievable by almost anyone with some basic mechanical skill.

Here is a shot of the upgraded metal hinge:

The basic steps are outlined below:

1) Remove the Windshield Wiper Arm Nut Covers.

2) Remove the Windshield Wiper arm Nut.

3) Remove the wiper arms, If the arms do not come off easy there is a specialty tool available designed to pull the wiper arm off.

4)  Remove the Air inlet grille panel (Cowl Panel) by removing the push-pin fasteners and then lifting up and disconnecting the wiper fluid hose.

5)  Disconnect the wiring connector from the windshield wiper motor.

6) Remove the bolts that attach the whole wiper transmission/motor assembly to the car. Remove the whole assembly (Wiper Motor and Transmission Linkage) From the vehicle.

7)  Remove the Wiper Motor Crank Arm Nut. (The nut which comes out of the center of the wiper motor) and remove the crank arm from the motor.

8 ) Remove the bolts which attach the wiper motor to the transmission/linkage assembly and remove wiper motor from the assembly.

9) Install the wiper motor onto the new transmission/linkage assembly. Install the crank-arm and crank-arm nut.

10) Reverse removal instructions to install the assembly and cowl panel back into the vehicle.

11) Reinstall Wiper blade arms, be sure that the wiper motor is in full park position (where they sit when the wiper switch is off), align the wiper arms and tighten the wiper arm retaining nut.

Written By Joe Stepnicka

Mercury Grand Marquis:  1992 – 2007

Ford Crown Victoria:  1992 – 2007

Lincoln Town Car:  1990 – 2005

Caution! : Working with coil springs can be dangerous. Read and understand these instructions completely before beginning work on the vehicle. Removing original air bags:

1)      Turn off Air suspension switch inside the trunk of the vehicle.

2)      Jack up vehicle and support the FRAME of the vehicle on jack stands. The rear axle assembly MUST be completely unloaded (in other words, hanging freely).

3)      Remove rear wheels

4)      Remove air spring solenoid retaining clip, it is a C shaped metal clip that easily pops off with a small screwdriver.

5)      Rotate the solenoid counterclockwise to its first stop. Pull outward on the solenoid to release the air pressure in the bag. Once the air pressure is fully released, rotate counterclockwise again and pull out, the solenoid will now come out of the air spring.

6)      Remove the large metal clip on top of the air-spring. This clip holds the top of the air-spring to the chassis. A pair of pliers or a large hook shaped tool may be required to remove the Spring-Clip.

7)      Release the lower air-spring seat by prying up on the air spring. The metal clip inside will release from the rear differential housing.

8 )    Unplug the electrical connector on the air-spring solenoid. Remove air line from air-spring solenoid by pushing down on the orange quick-release ring and pull out on the air line at the same time.

Installing New Coil Springs:

1)      With old air springs completely removed. Remove the lower shock mounting bolts. The axle assembly will now hang freely. Install the rubber coil spring isolators on the springs-seats and place the coil springs onto the isolators.

2)      Use a floor jack placed under the center of the differential housing (pumpkin) and slowly jack up the rear axle until the holes for the lower shock bolts are lined up with the shock.

3)      Install the lower shock bolts and tighten to 70ft/lbs. Lower the jack under the rear differential.

4)      Reinstall the wheel assemblies and lower the vehicle to the ground. Torque the rear wheels to 100ft/lbs.

5)      Disconnect  the air suspension computer. On some models it is located behind the trunk carpet. On others it is located behind the glove-box lid.

Chevrolet Trailblazer 2002 – 2009

GMC Envoy 2002 - 2009

Chevrolet Trailblazer EXT 2002 – 2006

GMC Envoy ESV 2002 - 2006

Note the small back doors, but NO REAR SEAT

Regular Cab DRIVER Side Window Motor / Regulator

Regular Cab PASSENGER Side Window Motor / Regulator

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The Super Cab has slightly larger small rear doors,, and a SMALL REAR SEAT

Super Cab DRIVER side window motor / regulator

Super Cab PASSENGER side window motor / regulator

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The Super Crew has 4 Full size Doors, and Full size rear seats.

Super Crew DRIVER FRONT window motor / regulator

Super Crew PASSENGER FRONT window motor / regulator

                The first thing I need to talk about is the proper equipment used to service an air conditioning system. Most of the system can be serviced using common hand tools, but there are a few specialty tools needed for proper service of your AC system.                                      

                The three tools shown above are critical to a proper AC repair. Before any repairs can be done on the AC system, the old refrigerant MUST be recovered. The only way to properly do this is with a recovery system such as the one above. This is actually required by law, so don’t skip this step. The vacuum pump is used after the repairs have been made, it pulls all air and moisture out of the system, so that when the system is refilled, only refrigerant goes into the system. The tools shown above are not tools that the average at home mechanic has, so if you don’t like the idea of shelling out big bucks to buy this equipment, you can always bring your car to a repair shop and pay a small amount to let them do the Recovery before you begin repairs, and the vacuum after the repairs.

                 The most common misconception about car AC is that cold air is created. Technically heat is being removed from the air. Although it sounds like a little nitpicky detail, it is actually quite important in understanding how the system in your car keeps you cool during the summer.

                In my explanations I am going to use the word “Refrigerant” a lot. Many people call it “Freon” but Freon was technically R12, which has been all but eliminated from use today due to environmental reasons (remember the ozone layer?). R134a is the most commonly used refrigerant today, but there is talk of changing to another version soon. So to make things simple I will simply say “refrigerant” in reference to all types.

If you look at the diagram above, you will see the arrows which show the direction that refrigerant flows through your AC system.  There are slight variations between some systems, but this diagram is a good overall view of a generic AC system.  This setup is typical for most imports and a few domestic cars.

                Follow along with me as I follow the flow of refrigerant and explain what happens as it goes through your system (if you have an orifice tube system, there will be some slight differences which I will explain in a bit). Starting at the compressor, the refrigerant is “compressed” into a high pressure, high temperature gas, typically about 200psi. From there it immediately flows into the condenser. The condenser has a single function, to “condense” the gas. It does this by cooling the high-pressure, high temperature gas. When the refrigerant is cooled, it turns from a gas into a liquid. The high-pressure refrigerant, now in liquid form then flows into the receiver dryer. The receiver dryer has two functions, the first thing it does is “Dry” the refrigerant. Inside the receiver dryer is a desiccant bag, this absorbs any moisture that may have contaminated the refrigerant.  The receiver dryer also stores liquid refrigerant as it comes out of the condenser. Once the refrigerant leaves the receiver dryer, it flows to the expansion valve. This little device is absolutely critical to the function of the system. And it is very simple in how it does it.

                    Expansion Valve

The expansion valve is simply an adjustable hole for the refrigerant to flow through.  There is a small temperature bulb which attaches to the outlet pipe from the evaporator, and will open and close the opening inside of the expansion valve depending on the temperature of the evaporator. If you look at the diagram above, you will see that the color of the tubing turns to blue after the expansion valve. That is because the hole for the refrigerant to flow through is so small, only a little amount can pass through at any one time. The blue lines indicate low pressure, one side of the expansion valve will be around 200psi and the other side will be around 35psi. This now low pressure liquid refrigerant flows from the expansion valve directly into the evaporator.

The evaporator does exactly what you would think, it evaporates. As the now low pressure refrigerant enters the evaporator, it literally starts to boil. Unlike water, which boils at 100 degrees Celsius, R134a boils at -26.3 degrees Celsius. As soon as the refrigerant drops to a low pressure, it is free to boil. Inside the evaporator intense boiling takes place as the R134a changes from a liquid back into a gas. A side effect of boiling is the absorption of heat. Heat is absorbed into the boiling refrigerant which causes the evaporator itself to become very cold as the heat around it is sucked into the boiling refrigerant. As the refrigerant leaves the evaporator, it is now a low pressure gas at which point it returns to the compressor to begin the journey again.

Meanwhile there are a couple other components which are critical to the proper operation of the AC system. The blower motor and fan push air through the cooled evaporator. Heat from inside the car is absorbed by the cool evaporator and then pushed back out into the car through the AC vents in the form of cold air. The condenser fan draws air from outside the car, and passes it over the condenser. This allows the condensation process which converts the high pressure gas back into a liquid.

Inside the dash of your vehicle are many air ducts. These ducts direct the airflow to the various vents in your car such as the defroster, or towards your feet when the heat is on. The direction of the airflow is controlled by doors inside the ductwork called mode doors.  Your vehicle also has a temperature blend door which varies the amount of air which passes through the cold evaporator and the hot heater core to change the temperature of the air coming out of the vents. Some cars have computer controlled AC systems that can automatically adjust the position of the blend and mode doors depending on the desired AC temperature setting.

If the system is not cold, the most common reason, but definitely not the only reason is that the system has run low on refrigerant. When the system gets low on refrigerant, the ONLY cause can be that you have a leak somewhere. It may be a very small hard to detect leak or it could be a gaping hole in one of your hoses. Using a sniffer is the best way to detect a refrigerant leak. Most individuals don’t have one personally, so often it is best to have a shop find the leak for you.

Numerous other causes can cause the system to not be cold enough to your liking. These causes can be anything from a blend door not operating correctly, to a radiator fan going bad and not pulling enough airflow through the condenser.

A VERY common problem in modern cars is that the fan speed selector only works on high speed. When this happens, 98% of the time it is caused by a failed blower motor resistor.  The blower motor resistor has various paths for the electrical current to take, each of these paths has a different level of resistance, that level of resistance causes the fan to run at different speeds depending on what path the electrical current has to take.

In the picture above, you can see the various curled wires on this blower motor resistor, the varying thickness and length of the wire is what causes different fan speeds depending on which setting the fan switch is currently on. When the fan is on HIGH, electrical current completely bypasses the resistor and goes straight to the blower motor, which is why HIGH is often the only setting that works.

Even with today’s outstanding technological advances, car AC systems are still prone to the same problems that have always been present. When working properly you will never think about what a complex system exists just to keep you cool on those hot days. Above are just two of the most common problems with car AC’s, I cannot get into every one as every manufacturer has its common quirks. There are so many variables in an AC system that if you are not 100% sure in what is causing the problem, I HIGHLY recommend bringing it to a shop with an ASE certified AC technician to diagnose your problem. This can save you headache and money and help get your AC working like new again.

Written by Joe Stepnicka

This article may not be reproduced without the author’s written permission.

If any of the above points on the shaft have failed, then the entire shaft must be replaced. For the longest time they were only available through the dealership, now www.autopartsdirecttoyou.com has them available for a much better price than going through the Dodge dealer. They have the following shafts available:

1997 - 2000 Dodge Dakota 4×2 2WD

1997 - 2000 Dodge Durango 4×2 2WD

1997 - 2000 Dodge Dakota 4×4 4WD

1997 - 2000 Dodge Durango 4×4 4WD

Their steering shaft has been redesigned with upgraded u-joints to prevent future failure. Their kits also replace the entire assembly, both upper and lower intermediate shafts, not just the lower intermediate shaft. This new shaft was designed to last the life of your truck, so you will never have an issue with the steering shaft again once replaced. The factory part numbers it replaces are 52078808AC and 52078808AD

When the shaft fails, it can cause a few different symptoms. The most common is a popping, or clunking noise when turning the steering wheel. If the vehicle continues to be driven in this condition, the symptoms will only get worse, eventually the steering wheel will develop a lot of slop, or play when turning the wheel. And after that, the steering wheel may begin to bind in your Dakota or Durango. A binding steering wheel can be a serious and dangerous situation, that is why you do not want to let your vehicle get to that stage if it is beginning to show any symptoms of the indermediate steering shaft going bad.

Written by Joe Stepnicka

Article may not be reproduced without without author’s written permission. �

If the relay has failed more than once, there is a very good chance that you have something else going on in your cooling fan circuit that is causing these repetitive failures.  

These solid state relays are extremely sensitive to various conditions. One of the most common reasons for failure is heat, if the relay becomes too hot, it can overheat and instantly damage the internal circuitry. This can usually be solved by insuring there is a very clean surface between the bottom of the relay and the chassis where it mounts. An optional step, but a good idea is to use a thermal-transfer paste on the underside of the relay. This thermal paste allowed heat to conduct more easily from the relay to the chassis. You can pick this paste up at a local Radio Shack or computer store. The relay gets rid of it’s heat by transferring it to the vehicle’s chassis, and the more efficient it can transfer heat, the cooler it will stay.

Typical thermal grease.

Another important factor is that the connector (often called pigtail) is in good condition, if the pins inside the connector are corroded or damaged at all, it will cause a higher resistance at the point where the connector contacts the relay pin. This again will cause excessive heat and can quickly burn up a brand new relay. A poor connection can also cause voltage spikes which are extremely hard on any solid state device. The kits sold from www.autopartsdirecttoyou.com include a brand new connector that MUST be replaced when installing the relay. This will help insure the relay will continue to operate trouble free.

 The third thing that can cause repeated failure of the fan relay, is if the cooling fan itself is going bad.  If the cooling fan is starting to fail, often it will draw more eletrical current than a fan in good condition. When this happens, it places a much heavier load upon the cooling fan relay, which again will cause the relay to overheat and fail. The simplest test to see if the fan may be going bad is to manually spin the blades (Only do this if you have the battery disconnected to prevent injury!). If the blade feels tight at all, or if it feels as if it is binding in any spot, then you need to replace the fan. It can also fail internally without any physical symptoms as described prior. The only way to tell this is to do an amperage test on the fan while it is running to check how much current the fan is drawing. If the fan draws more than 20 Amps at max, then you have a problem with it and need to replace it or you will continue burning up the relays.

Written by Joe Stepnicka.

 Article may not be reproduced without authors written permission.

                If you are replacing the compressor in your vehicle these are a few critical steps that must be taken before installing a new compressor. These are not just suggestions, they are requirements. And your compressor warranty depends on it!

a)      Clean your internals! In the case that the compressor has come apart internally, there is likely debris now scattered throughout the inside of your AC system. The place where the majority of this debris is usually collected is inside of the condenser. Many technicians prefer to replace the condenser when a compressor has come apart internally. This prevents the possibility of debris re circulating through the system and destroying your new compressor. Another option is to flush the condenser, hoses, and evaporator with a flushing solvent.  A flush solvent can be bought at most auto supply stores to safely remove any debris located inside the system.

b)      Unclog that tube. An AC system has one particularly vulnerable component that must be replaced when replacing a failed compressor. Depending on the type of system, your car either has an orifice tube, or an expansion valve. This component is the smallest part of the entire system that refrigerant must circulate through. It only takes the smallest piece of debris to block it and cause an inoperative AC system. That is why it is crucial to replace the orifice tube or expansion valve when replacing the compressor.

c)       Keep it dry. ANY time you open the AC system is it important to replace the Drier or Accumulator (your car has one or the other depending on the type of your system). The drier and accumulator have a desiccant bag inside which removes any small amount of moisture that has introduced itself into the system.  Moisture trapped inside the AC system can cause devastating effects to your new compressor, and can also reduce the efficiency of the system as a whole.

d)      Lube it up. If the new compressor you are installing is not prefilled with oil, it is CRITICAL to refill the new compressor with the proper amount and type of oil. Refer to your service manual for your specific type and quantity of AC oil.

e)      Suck it down. Prior to refilling your new system with refrigerant, it is very important to place a vacuum on the system. This will remove all air and moisture from the system so that only pure refrigerant is present when you refill the system. It is recommended to allow the system to be on a vacuum pump for at least an hour after the system has been opened.

New Oxygen Sensor

Modern fuel injected engines depend on a large number of factors to keep the engine running smooth and efficient.  One of the most important factors in this complicated process comes from the oxygen sensors. The oxygen sensors send data to the computer to help it determine whether the engine is running rich (too much fuel) or lean (too little fuel) and the computer can then make the proper adjustments to the fuel ratio.

Oxygen sensors (o2 Sensors) have been used in almost every car since the early 1980’s. They have progressed technologically to the efficient and reliable state that they are today. Oxygen sensors depend on being hot in order to work properly, the original sensors would not work until the heat from the exhaust actually heated them up enough to start working. During that heat up time, the computer could not use the oxygen sensor data to help determine the fuel ratio. This would cause early fuel injected engines to be very inefficient until the exhaust has heated up the oxygen sensor enough to allow it to start working. Modern sensors actually have a built in heater which very quickly heats the sensing element inside the oxygen sensor so that it can begin sending data almost immediately to the computer after start-up.

For many people the terminology used to explain oxygen sensor locations can be intimidating but it’s actually quite simple. They are usually listed one of two different ways, the more common way is, for example, Upstream bank 1, or Downstream bank 2 etc. This odd sounding terminology is actually quite simple to understand. The ‘Bank’ is simply a way of explaining which side of the engine the sensor is on. Bank 1 is always the side that has cylinder number 1 on it, you may have to reference a firing order diagram to determine where cylinder number one is. Bank 2 is always the side opposite of bank 1. Upstream and Downstream are even easier. Upstream simply means before the catalytic converter (closer to the engine), while downstream means after the converter (closer to the tailpipe). So here is an example, if you want to replace the Upstream bank 2 sensor, you simply find the number one cylinder, go to the opposite side of the engine, and the correct sensor is the one in the exhaust closest to the engine. But wait, there’s more! Another terminology common to Oxygen Sensors looks like so: B1S2, B2S1 or B1S1. This is actually easy to understand as well, the B# stands for Bank # , and the S# stands for Sensor #. the Bank is the same as the previous example, and for the sensor number, S1 means upstream (before the converter), S2 means downstream (after the converter). So if you see B1S2 that means the sensor on Bank 1 After the Catalytic Converter.

So what’s the difference between upstream and downstream oxygen sensors? Actually quite a bit. They both have unique functions, the upstream sensors’ main function is to monitor the air fuel ratio coming directly out of the engine, and use that data to help the engine perform properly. The downstream sensors, however, have a completely different use. Their primary task is to monitor how effectively the catalytic converter(s) are working. When a catalytic converter is working properly, the downstream oxygen sensor will output a relatively steady voltage of about .5 volts (after everything is at optimal temperature). If the converter is going bad, the voltage coming from the downstream sensor will be almost identical to the voltage coming from the upstream, which fluctuates between .2 and .8 volts while the engine is running.

Oxygen sensors fail for a number of reasons, one of the most common failures in modern sensors is the built in heater failing. When the heater fails, the sensor becomes like the older ones and depends on the exhaust to heat it up before it begins working which again causes the engine to run inefficiently until the sensor heats up fully. All cars after 1996 are designed to monitor the heaters inside the oxygen sensor, and will turn on your check engine light if they detect a problem with any of them. Another common failure of o2 sensors is caused from the buildup of carbon and foreign material on the sensor itself. Over time this can cause the sensor to become “sluggish” in it’s response time, which can can also affect performance and fuel economy. The computer will usually turn on the check engine light when it detects that the sensor is responding sluggishly. There is no way to clean or repair the sensor once it becomes sluggish and must therefore be replaced.

After years of usage, oxygen sensors can degrade in performance  yet not cause your check engine light to come on. If the computer “assumes” the sensors are working properly, but they are really sending inacurate data, the computer will make adjustments to the fuel ratio that should not be made. This can also cause numerous problems, from decreased fuel economy, to poor running condition.

Oxygen sensors are subjected to severe conditions throughout their life in your vehicle.  Over time the constant exposure to temperatures as high as 1,000 Degrees Fahrenheit as well as carbon buildup on the sensor, will cause the sensor to be slow to respond and less accurate. This can cause a reduction in performance, and a drastic drop in fuel efficiency.

 Old worn oxygen sensor.

                Replace your Oxygen Sensors every 60,000 – 100,000 miles to help keep your engine running in peak condition and prevent future problems. You can order brand new oxygen sensors for your car here: www.autopartsdirect2you.com

- Joe Stepnicka

-www.autopartsdirecttoyou.com

-Duplication of part or all of this article is strictly prohibited without the author’s written permission.