Purchasing a Tester

For those who continually invest money in tools for their job, here’s a piece of equipment that is a must have item. There are several different types of electronic charging system testers out there, this one is from Mac tools. These testers vary in price from $199-$399. The great thing about electronic charging system testers, is the ability to test and have results within 2 minutes.

Having the correct tools for the job is the most important part of diagnosing and repairing automobiles. Testing the battery, starter, and alternator is an area where improper diagnosis can be costly. With the correct tester this job can be diagnosed within a couple of minutes.

Before testing the battery or any other electrical issues, making sure there is voltage present with no corrosion or poor connections is the first step into diagnosis. For more battery and electrical maintenance tips refer to the following posts:

• Battery Knowledge
• Battery Cleaning
• Check, Test, and Replace a bad car Battery

Here is a step by step procedure on how to perform the 3 individual component tests that makeup your charging system. The tester used in this article is the Accuracy Plus tester from Mac tools.

1-The Battery Test

Hook up the battery tester color coded clamps. Red to the positive terminal of the battery and black to the negative terminal of the battery.

Once powered up, the tester will guide you through each step of testing.

The first thing the tester will ask is what the CCA or cold cranking amps are.

Input the amount indicated on the battery and press go. (Battery rating – 550 CCA)

This is the amount that the tester will “load” or take away from the battery to see if it meets the rated capacity.

After pressing go, the tester will load the battery two times within 20 seconds. Then it will show “battery good” or “battery bad” on the display and the actual amount of voltage and CCA’s tested. It’s that easy.

Battery condition good.

Test results, 12.6 volts and 510 cold cranking amps.

Battery Test Results

If this battery was bad, it would show low cranking amps. 510/550 is a good test result. If the voltage tests lower than 12.0 volts, the battery should be charged and re-tested.

2-Starter Test

Immediately following the battery test, the tester will instruct you to start the vehicle.

At this point the starter current draw will automatically be tested. (The starter results will show up at the end of the last test)

Starter Test Results

Good test results should be no more than 150 amps of current draw. Any amount over 200 amps could put excess drain on the battery. This could cause problems during the winter months and may even shorted the life of the battery over time.

3-Alternator Test

This is the final of the 3 tests for the complete charging system.

With the vehicle running, you will be asked to press go and increase the throttle to 1500 RPM. During this time (approx. 15 seconds) either jump in the car and rev up the engine…

…or look for the throttle cable on the engine. Increase the RPM slowly until the tester tells you to maintain the RPM.

The alternator will automatically be tested by simulating the maximum amount of load devices that could be turned on from your vehicle and record the output. It will also test the internal voltage regulator functions as well.

Here is the measurement of output from the alternator under a load test. (14.2 volts)

Alternator Test Results

Good results would be an increase in voltage by approximately 2.0 volts. (12.5 volts before starting, 14.5 volts running) The tester will show “diodes good” or “diodes bad” as a result also.

Final Results

When the test is finished, you will be instructed to turn the vehicle off. The complete evaluation of the charging system will scroll through for you to read. Here are the items tested:

• Battery load test – with voltage and CCA results
• Starter current draw test – with amount of amperage and voltage used
• Alternator output test – results with load and no load voltage and amperage output
• Alternator/Regulator – internal function test of the voltage regulator diodes

Final Thought

This tester is one of the most user friendly testers available. It’s also one of my favorite pieces of test equipment to use. If there are any electrical problems found on the vehicle being tested, the tester will tell you and stop with any further tests. This allows you to replace the faulty part and retest after the problem is fixed.

Here is a 2000 Ford Windstar with a 3.0 liter V-6. The customer concerns were… “when going to start the vehicle first thing in the morning, the car just clicks”. “Another strange thing that happened was the interior lights would turn on and off by itself”.

Safety First

When working around car batteries, always take precautions with handling batteries. Wear eye protection and gloves to prevent any debris or acid from getting on your hands or being rubbed into your eyes!!

Needed parts and tools for the job:

You will need the following new parts and tools to perform this repair;

• 1-Battery
• 1-Digital volt and amp meter
• 1-10mm wrench
• 1-1/4” ratchet with 5/16” socket
• 1-pair of safety glasses
• 1-pair of gloves

Price Comparison – How much you can save

Repair shop pricing
Parts-approx.$100-$120
Labor to diagnose and replace battery 1 hour($80)
Total cost-$180-$200 plus tax

Do it yourself
Parts-$50-$90 (from your local parts store)
Estimate time to repair, approx 30 min.
Total cost-$50-$90 plus tax

Verify the Customer Concern

Separate of turning the key to crank the engine, the best pre-test to perform is with a digital volt meter.

Locate the old battery and check the battery terminal ends for corrosion. (If corrosion is present, you’ll need to clean before testing)

Note:

Refer to battery maintenance for tips and advise on how to clean a battery .

Here’s an affordable digital volt and amp meter you can purchase for around $59 from Sears.

Turn the meter knob to the DC volt setting. Connect the red meter lead to the positive or + terminal of the battery.

Connect the black meter lead to the negative or – terminal of the battery. Here we show 3.1 volts in a battery that should show 12.5 volts.

This battery is more than 4 years old, so it’s not worth trying to charge just to see if the voltage comes up.

Note: 90% of all car batteries fail within 5 years.

Remove the old battery and replace with an equal if not higher strength battery.

Locate the Cold Cranking Amp rating on the battery. (CCA)

This one is a 550 CCA battery.

Install the new battery into the battery tray.

Install the positive terminal end and tighten the 10mm nut.

Install the negative terminal end and tighten the 10mm nut.

Install the battery hold down and tighten with a 5/16″” socket and ratchet.

Test the new battery with the volt meter the same way you tested the old battery.

Start the engine and watch the voltage on the meter. Before starting, the voltage should be at 12.5 volts. When running the voltage should be at 14.5. The 2 volt increase is a sign that the alternator is charging.

When jumping a vehicles battery, the reason is either that something electrical was left on and ran the battery down or the battery has electrically failed and won’t power up your vehicle. Car batteries have a combination of lead plates, water, and sulfuric acid. A chemical reaction produced when the battery is electrically charged will provide the necessary power for your vehicle’s electrical system.

When a battery runs down or becomes discharged, the sudden charge from jump starting or quick charging produces a hydrogen gas within the battery. All batteries have vents to prevent the battery gasses from building up or causing the case to swell. These vents will allow hydrogen gases to release at and around the battery. Whenever making a connection at the battery, if the jumping source is powered, sparks can occur which could ignite the gasses present creating an explosion. When following this post, make sure not to hook up the cables backwards or ground out a power source other wise severe electrical damage will occurr!!

For more battery knowledge, refer to the battery maintenance post “How to section”

To locate a pair of jumper cables, use one of the parts links and search ‘jumper cables’.
A good 20 foot pair will cost around $40, but will last a long time.

Make sure they’re long enough to reach the width of 2 vehicles. This will allow for enough cable to comfortably use.

Red is for the positive battery terminal and Black is for the Negative terminal

Make sure to separate the cable ends before making your first connection

Pull the cars close to each other and open the hoods
Make sure the dead car has the key off and the good car is running with the head lights on

Make the first connection the positive terminal on the running vehicle (look for a red cable and/or a + mark on the battery)

Make the second connection the negative terminal on the running vehicle (look for a black cable and/or a – mark on the battery)

Note:Make sure the jumper cables are routed away from any moving parts such as belts or fan blades

Make the third connection on the dead car positive terminal,(look for the red cable and/or + mark on the battery)

The fourth connection is the most important, ground it away from the battery

New cars typically have under hood positive and negative connection points
Remember the opening text about not creating sparks to prevent a possible explosion. Don’t go against the rules!!
It’s a safety thing!!!

Once the cables are connected, attempt to start the dead car. If the attempt does not start or cranks slow, wait for a minute or two and try again.

When started, remove the jumper cables in the reverse order. Remove starting with the jumped car ground 1st, positive 2nd, the good battery ground 3rd, and the positive 4th.

A better way to jump and a nice tool to have is a jump box.

Use one of the parts links and search ‘battery jump box’ they range from $45-$60

Most jump boxes fully charged have an indicator light built in to show the state of charge.

A nice feature is a cut off switch. Hooking up before turning on will eliminate any unexpected sparking.

Just like using jumper cables, the box is the reserve battery source and only needs to be connected to the dead car.

Some jump boxes have ends that can easily connect to a side post battery as well as a top post battery.

Make the first connection the positive terminal

Make the second connection the ground

Position the jump box where it won’t interfere with anything under the hood

Flip the power switch

Start the car

Now that’s much easier. For knowledge on maintaining and cleaning your battery

refer to the battery maintenance post “How to section”

Safety with Handling Battery’s

When working with and around batteries you need to be cautious about battery acid. Make sure that you always wear safety glasses and protective gloves when working around a battery that may have acid on the case, terminals, or battery tray. Here’s how to properly clean up and handle your car battery.
If you suspect that your battery may have a problem or just want to maintain optimum performance from your battery start by locating where the battery is.

Locate your battery

Some manufactures put batteries under the rear seat of the car, some in the back corner of the trunk, but most are under the hood next to the engine.

The most important thing is to have a clean battery. Most batteries that are dirty have dirt clung to acid which has leaked out though the battery vent or cell caps.

A dirty battery is a sign of problems about to happen, if the charging system is over charging the battery or if the battery has a crack in the case to allow battery acid to leak out.

A dirty battery or corroded terminal ends can cause an endless amount of electrical issues to your vehicle.

Cleaning a Battery

The best way to clean a battery is to buy battery cleaner and protector in an aerosol spray can from your local parts store.

A second alternative for cleaning the battery is baking soda.

Mix ½ a glass of water with 2-3 table spoons of baking soda and pour on battery and let sit for a minute then rinse with clean water.

Neutralizing the acid with baking soda is no different than you chewing up a couple of tums for heartburn.

When the battery is dry apply the protector to the connections at the battery.

Note: Keeping the battery clean will extend the life of your battery as well as eliminate the possibility of having any electrical issues while driving your vehicle.

Recommendations:

Keep an eye on the age of your battery, most batteries last between 3-5 years, so being aware of the life span of your battery can eliminate an unexpected breakdown or costly repairs.