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Replacing alternators 01/03/2011

I get a lot of questions about replacing alternators. The most popular of these questions is do I recommend replacing an alternator with a new or re-manufactured part. Back in early 90s my answer would have been neither.

We use to take an alternator apart and replace only the internal components that were needed. Replacement parts were readily available and also fairly inexpensive.

Most often when we tested these alternators we found either blown diodes or worn-out brushes. These parts were available for about $20 and the repairs were extremely reliable.

But on modern automobiles when the cause of the charging system failure is traced back to the alternator it should be removed and replaced. Most late-model alternators are not rebuilt anymore. They are traded in as a core towards the purchase of a new or re-manufactured unit.

Common check engine light problem 12/22/2010

A common check engine light problem that I run into often would be a set code for the evaporative emission control system. Sometimes this code is caused by a loose gas cap. I have also seen defective rubber seals on the cap itself trigger the code.

Please be aware that a gas cap is not the only problem that can set a check engine light code for this system. In fact vehicle manufacturers have actually made it much harder for a loose fuel cap to set a trouble code. But in the end it will still turn the check engine lamp on if it continues to leak fuel vapor.

This page will be about other causes of vapor leak codes. But if you are interested in more information on the loose or leaking fuel cap subject I have put together a gas cap code video that discusses this common check engine light problem. The video outlines steps you can take to correct the issue before spending time and money at the car repair center.

Heater Core Problems 12/12/2010

How automotive heating keeps you warm and some common heater core problems discussed. The automotive heating system has been designed to work together with the engines cooling system to maintain a comfortable temperature inside the passenger compartment.

Heater Core

The heaters primary job is to provide not only warmth but also to remove fog or frost from the windows on the vehicle.

The primary components of an automotive heating system are the heater core, the heater control valve, and the blower motor or the fan. These three items work together and push warm dry air out of three different destinations.

These are the vent ducts that point to the driver and passengers the defroster ducks that point towards the inside surface of the glass and a floor heater duct that usually points down towards the carpet or flooring.

The heater duct is mounted low and pointed down because hot air rises. When the warm air is released at its lowest point possible it will then rise towards the headliner and warm the interior compartment on its way up.

How the heating system works

Cigarette lighter problems 12/02/2010

Cigarette lighter problems can be a big issue because this power outlet is now used for so many other devices. It is also this fact that makes cigarette lighter problems more common today than ever. Most of the times this circuit is protected by a 20 amp fuse.

blown fuse

Spikes in amperage can cause this fuse to blow and the outlet to become inoperative. If you depend on the cigarette lighter to charge your cell phone or run iPod car accessories and other high-tech gadgets you may find yourself banging on the dashboard in frustration.

You can check with your owners manual to find out the location of the cigarette lighter fuse. On some vehicles is not called the cigarette lighter fuse and may be considered a courtesy fuse. In the old days most fuse panels were under the dash near the drivers area. On modern vehicles fuse panels can be commonly found in the engine compartment.

Cigarette lighter blows fuses

Automotive Heating System Problems 11/22/2010

Automotive heating system problems are usually related to the engine cooling system. Hot engine coolant is diverted to the heater core through some type of heater control valve. The core itself fits inside a plastic case and has an inlet hose and an outlet hose.

stuck open thermostat

In most cases both of these hoses are visible from the firewall on the engine compartment side of the vehicle. The inlet hose should be hot when the engine is at full operating temperature. The outlet hose from the heater core should be warm even when the blower motor is on high and the heat mode is selected. When I have a customer complaint about automotive heating system problems like lack of heat in the interior compartment in most cases I find a problem with the cooling system.

Many times I find low coolant due to a system leak. In some cases a stuck open thermostat can also cause this lack of heat condition. When the thermostat is stuck open all of the engine compartment cooling hoses will be cooler than normal.

Automatic Transmission Diagnosis 11/12/2010

Basic automatic transmission diagnosis should start with some investigative groundwork. Often driver complaints about transmission problems can actually be traced back to malfunctions in other parts of the car.

automatic transmission

You also should take the time before beginning any diagnosis to be sure you know exactly which unit is installed in the specific vehicle. Often technical service bulletins about certain model transmissions can provide a lot of insight on common problems associated with that model.

Knowing the year and model of the vehicle may not be good enough for positive identification of the installed unit. Some manufacturers will perform up grades or even change the models during the manufacturing year. The only positive way to identify the exact one installed in your vehicle is to get the identification numbers off the transmission itself.

Diagnosing Electrical Engine Control Systems 11/02/2010

Diagnosing electrical engine control systems involves much more than accessing the stored trouble codes in the computer memory. As is true during diagnosis of any system you need to know what to test when to test it and how to test it.

Diagnosing engine codes

Because the capabilities of the engine control computer have evolved from simple to complex it is important to learn everything you can about the system the set trouble code refers to before attempting to diagnose a specific problem. Referring to a vehicle specific service manual for this information is highly recommended.

After you have studied and completely understand the system and its capabilities you can then begin your diagnosis using basic and logical methods. I cannot over emphasize the importance of logical troubleshooting. The ability to diagnose a problem that will lead you to the cause of the malfunction and its eventual solution is what separates an automotive technician from a parts changer.

Using logical diagnosis

Fleet Maintenance Technicians 10/21/2010

For the last five years I have been a Fleet maintenance technician. This has probably been one of the best jobs I have ever had. It may not be the most fun but it is a good way to make a living. In my Fleet we mostly deal with trucks and most of them are domestic vehicles.

Fleet Maintenance Technician

After working on the specific vehicles for a couple of years I think it is safe to say that I am an expert on Ford, Chevrolet and Dodge pickup trucks as well as some heavy duty diesel trucks. It is not because I am smart it is because I have not worked on anything else for several years.

In fact after replacing the water pump on a 7.4 L power stroke diesel ford engine for the 10th time not only can I do it quickly I could just about do it with my eyes closed. Each time I performed the repair I would learn short cuts and better techniques for replacing the water pump on the power stroke. I was even able to stop following the procedure in the service manual.

O2 sensor problems 10/12/2010