Barrow, Alaska, generally is recognized as the coldest spot in the United States. Its average temperature is a balmy 11.7 degrees Fahrenheit and has a recorded best low temperature of -56 degrees Fahrenheit. On the other side of the coin, the world record for high temperature is 134 degrees Fahrenheit, and a few cities in California were close to breaking that mark during the heat waves experienced this past summer. And while this article is going to talk about preparing for the low side of the scale, many of the tips shared apply equally to hot or cold climates.
Let’s Start With The Battery
A battery provides electromotive potential via a chemical reaction, and that reaction slows as temperature drops and increases as temperatures rise. Compared to a standard temperature of 77 degrees Fahrenheit, a battery that hits freezing will typically produce 20 percent less energy, and at -22 degrees, the capacity can be cut in half.
This alternator may be rated for 110 amps, but it is not designed to deliver high current for an extended time. Test the recharge current as part of your overall charging system analysis.
But it’s not just the cold. According to a 2010 Battery Council International (BCI) failure mode study, even though batteries have become more heat tolerant over the last decade or so, heat can still have a drastic impact on the life of the battery. Back in 2000, a change of just 12 degrees Fahrenheit took roughly one year off of the battery’s estimated lifespan. In 2010, it takes a 22-degree change to have the same impact. Overall, improvements in battery design have resulted in an average lifespan of roughly 55 months (compared with an average of 41 months during in the 2000 study). And you might be surprised to learn that batteries in the South are used up (with an average of 47 months) long before their northern cousins (averaging 59 months).
To help make sure your customer’s battery will deliver as promised, perform a complete battery/charging system test. All you’ll need to do a complete set of tests is a digital multimeter (DMM) and an amp clamp.
The battery might start the car fine while the weather is warm, but any weakness in it will be magnified when the mercury heads south.
Start by measuring the Open Circuit Voltage (OCV) of the battery. A fully charged battery with healthy electrolyte should read 12.66 volts (2.11 volts per cell). This is an indication of the state of charge of the battery. If your meter reads more than 12.8 volts, there is a surface charge on the battery. This also can tell us something about its condition. Surface charges higher than 13.5 volts or so can indicate that water has been depleted from the electrolyte, due to evaporation or overheating. If the fluid level has dropped low enough to expose the plates even a little bit, it’s a good idea to replace the battery. If the plates are still submerged and you can access the cells, use a syringe to add water (distilled only please) to just below the vent well. A reading of 12.5 volts or less indicates a battery that is discharged more than 20 percent, and you must recharge the battery before proceeding with a load test. An OCV reading of less than 10.5 volts indicates a shorted cell and the battery should be replaced.
Be sure to test the battery connections. Look for (and clean) terminal corrosion and the battery case. Corrosion on the terminals is usually caused by outgassing of the electrolyte and might indicate a leak in the battery casing. Dirt and grease on the case (if it forms a path between the posts) can be a source of battery drain and accelerate the wear and tear on the battery. Perform a voltage drop test on both the positive side of the starter circuit (one lead at the positive post and one lead at the end of the starter cable where it attaches to the starter) and on the ground side of the same circuit (one lead at the negative battery post and the other on the starter case). Be sure to have an assistant crank the engine while you’re testing. Voltage drop tests must be done with the circuit on. Correct the cause of any excessive drop found.
The next step is to perform a cranking voltage test. Unlike a carbon pile load test, this test only applies a load to the battery for a few seconds. With your DMM still connected, turn on the meter’s record (or MIN/MAX) feature and crank the engine. Repeat the process three times, allowing the engine to run for a few extra seconds on the last cycle before turning it off. Your minimum reading should be above 10.0 volts (as opposed to the 9.5 volts for a 15-second carbon pile load test). Anything less than 10.0 volts indicates a battery that has reduced capacity.
The best way to check the coolant mixture ratio is with a refractometer. Coolant test strips rank No. 2.
But before you recommend a replacement, be sure to consider the battery’s temperature when you tested it. If it didn’t meet 10.0 volts while it was still in the 70s, you are certainly doing your customer a favor when you recommend a new one before the weather drops to the 20s.
Now check your meter’s MAX recording. This is charging system voltage and should fall between 13.5-15.0 volts. Refer to the OEM service specifications for your specific vehicle, as some cars use intelligent charging strategies that initially charge at a higher rate than you may be used to seeing.
The last test is the battery recharge current test. This is where you’ll need an accurate amp clamp. When the engine is started, the battery is temporarily depleted. As soon as the engine begins to run, the alternator comes on line to replenish what was lost. Initially, the NET current (the total difference between system demand and alternator output) flowing into the battery can be substantial but it should only take a few minutes (allow five) for a good battery to recover. The NET current flow then should drop to less than 10 amps (some sources say 3 amps). The lower the number, the better it is for the health of the generator. If the number remains high (caused by an internal fault in the battery, typically sulfation), the generator can overheat and fail. (OK, now you know why Mr. Johnson has had four different alternators in the last three months).
Coolant
Coolants provide important protection for the engine and, on hybrids, for the high voltage electrical systems. Well, the water does most of the cooling. The coolant is added to the water to enhance both boil-over and freeze points. In addition, inhibitors in the coolant protect system components from corrosion and erosion. With all the important work coolant has to do, don’t rely on a simple visual check of the coolant bottle’s fluid level alone.
Coolant test strips can be used to test coolant mixture and acidity; the two key factors you need to determine whether or not the system requires service.
We can, though, start there. Check both the level and condition of the coolant in the reservoir. Low levels happen for one reason only: leakage. So if the level is low, be sure to determine why it’s low and correct the problem. Low coolant levels promote air in the system and coolant can’t protect what it can’t touch. Debris in the tank, too, can only come from one place and is evidence of a cooling system that has received less attention than it should have.
Next, check the water/coolant mix with (in order of preference, best to worst) a refractometer, test strip or gauge-style hydrometer. No ball-type hydrometers please and take your sample from the system and not the reservoir. A coolant mix in the 40 to 60 percent range is considered acceptable. Follow up that check with a check of the pH, or acidity, of the coolant. The pH is an indication of the health of the inhibitors. Typically, the coolant will become more acidic as the inhibitors drop out. If the coolant passes this test as well, your customer’s coolant should be ready for the winter ahead. On the other hand, if the coolant is too acidic (or too alkaline), a coolant flush and refill with fresh coolant is needed to insure system protection.
A quick couple of notes on cooling system service for you. First, water makes up half of the mixture so be sure to use water that meets specifications for both the flushing procedure and for the refill. There are test strips you can buy to check your shop’s water supply and you should do it periodically to make sure it’s OK. But the water in your shop is drinking water and is not suitable for use when mixing up the refill. Why? It is oxygenated to make it taste better, and that same oxygen can lead to wear and tear in the system. For your 50/50 mix, use distilled water or buy coolant that is pre-mixed from the factory.
Even when it’s cold out, the air conditioning system has a job to do. Check the operation of both the A/C and heating systems to make sure your customer is ready for the winter ahead.
Two, coolant color is not indicative of the type of coolant in the system. Follow the OEM recommendations when selecting a replacement product. Three, coolant service intervals can be as high as 10 years or 150,000 miles for some makes, but that’s in a perfect world. Even extended life coolant can be worn out prematurely if the wrong water is used, air is prevalent in the system, leaks have been left alone and by a dozen other ways.
Of course, check over all the underhood fluids as well as the condition of the belts and hoses while you’re under there. Watch our coolant service webinar (on YouTube or in the AutoPro Workshop) to learn more about testing and identifying the causes of premature coolant failure.
Tires
Snow tires will be the norm in many parts of the country, and many drivers have a set mounted and stored to make the swap a simple one. Or is it? Changing tires on late model cars can impact the operation of a variety of safety systems, antilock brakes (ABS), traction control (TCS) and electronic stability control (ESC) for example. It also can impact the operation of the transmission with many models requiring you to tell the control module in charge what changes you made.
It can get hard to see in a snowstorm or heavy downpour, and clouded headlight lenses don’t help. This service is easy to perform and of real value to your customer.
And there’s the tire pressure monitoring system (TPMS) to consider. Will you take the sensors out of the summer wheels and install them into the winter ones? Or will you install one of the aftermarket clone-able sensors in the winter wheels? Clone-able? Yes, these are sensors that can mimic the originals (either through direct programming or preprogrammed), allowing you to install them in a set of winter wheels and then simply installing them on the car. The TPMS control module thinks it sees the same sensors as it saw in the summer wheels, so no relearn is necessary.
Be sure you review the OEM service information regarding all of these possibilities before agreeing to a simple swap for your customer. Make sure you have the tools, service information and parts you’ll need to do this “simple” job properly. You can find all the resources you need, including several instructional videos, on our web site. And don’t forget to change out that stale air for fresh air before installing the winter tires. After all, they’ve been sitting in the corner of his garage all summer long.
OK, you do know I was kidding about that last part, right?
A Few Other Checks to Make
Now also is a good time to make sure the Heating and Air Conditioning (HVAC) system is working properly. On many cars, the air conditioning system is used in defrost mode (regardless of temperature selection) to dehumidify the air and help prevent the window from fogging up. Hook up the pressure gauges and check the operation of the A/C system. Once you’ve verified the A/C is blowing cold and is coming out of the right ducts, crank the temperature control down to full heat and complete your performance inspection there. A lack of heat can be caused by air in the cooling system, a temperature blend door that is not functioning, or restrictions in the heater core flow.
Serpentine belts can look fine and still be worn out. Most belt makers offer these pocket tools to check EPDM belts for damage. This one is Dayco’s version.
Often overlooked is the cabin air filter. Once fitted to only higher-end cars, cabin air filters are the norm on more than 85 percent of the cars made since 2006. They not only keep the outside dirt, pollen and smog out of the cabin, they also help prevent debris from building on the evaporator core. Clogged filters can reduce the airflow through the vents and on some occasions have been responsible for the early demise of an a/c compressor.
Another overlooked item is the wiper blades. It seems our customers know full well they are worn and streaking the windshield, but then forget all about it once the weather has cleared. Visually inspect them for damage, then hit the washer function and see how well they clean and clear. While you’re focused on the wipers, make sure the wiper wash bottle is full of washer fluid. It, too, resists freezing. If all you see is water in the tank, advise your customer of the potential damage it could do to the washer motor. A small part but not always the easiest (or cheapest) to get to and replace.
What about the lights? Where I live, there is no mandatory state inspection and I see more cars with brake lights that don’t work then I do with lights that are totally functional. With inclement weather, the need to see and be seen is vitally important to the driver’s safety. Make sure all the lights work, including the brake lights. Check the condition of the headlight lenses. Clouded lenses reduce the light getting to the road and the fix is easy to do, using any of a dozen different products on the market. I used to use No. 400 grit sandpaper (wet) to get rid of most of the haze, followed by a fine polishing compound to get rid of the rest. The key to a successful headlight reconditioning is the use of a sealant afterward to protect the lens from hazing over again.
Your customers count on you (whether they admit or not) to keep them safe and to help them be ready for the seasons ahead. A little more focus on these key items can help you differentiate your shop from your competitors, winning you more business in both the short- and long-term.
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