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How to Avoid Summertime Electrical Failure On The Road

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With the summer months on the horizon, it is time to prepare for hitting the open road. Nothing is more satisfying after a long winter than an epic road trip with friends or family. The key to a successful journey is to complete it intact, and that means ensuring that your conveyance is properly prepared for summer temperatures. While winter’s cold can zap a battery, the high heat of summer can wreak havoc on your vehicle’s cooling and electrical systems faster than you can say “4 slushies, 6 hot dogs and burrito.” Here’s how to avoid summertime electrical failure when you are on the road.

Top 10 tips for summertime road readiness

Cooling System

The vehicle’s cooling system gets a serious workout when the mercury climbs past the 80s. Make sure it has passed these fitness tests before putting it to work in a marathon cross-country drive.

1.  Antifreeze and Water

Even though cold weather is in its name, antifreeze does more than just keep your water from freezing. It actually helps keep your engine’s cooling system running smoothly. Radiator coolant is formulated with lubricants and anti-corrosion agents to reduce the wear on the system. Additionally, antifreeze increases the boiling point of the water. This allows the coolant to absorb more heat, as any liquid coolant is only good until it boils.

Decreasing the surface tension of the engine coolant can make a big difference in cooling capability.

You can boost your coolant’s ability to function with a coolant additive, such as Royal Purples’ Purple Ice, which further reduces the surface tensions and helps lubricate your cooling systems moving parts.

All liquids have what is called “surface tension”, this is the property of the liquid that keeps it together and resists adhering to other substrates. A water strider on a pond is a good example; the bug does not sink because of surface tension. Inside your radiator, the same principle applies. There is a resistance between the metal surfaces and the water, which lowers the thermal conductivity. Reducing that resistance means your engine will operate cooler and more efficiently.

Don't neglect the overflow tank. Most modern engines use these to store additional engine coolant. Make sure it is filled to the correct level.

2.  Leak-free

A leaky cooling system is a ticking time bomb, don’t let it blow up in your face while crossing the country in the middle of nowhere. Even a small leak is a big warning sign. Check all of your connections to the cooling system – radiator, water neck (where the hose connects the engine to the radiator), even the heater hoses. Tighten any loose fittings and replace rusty hose clamps. Make sure you check the bottom of the water pump on the engine too; there is a weep hole at the bottom. If it is wet, the seals are leaking inside the pump, and you should check into having the pump replaced.

3.  Fan Blades

Most modern cars have electric cooling fans, but many trucks and most older cars have mechanical cooling fans. These are driven off the engine and they go bad. There is a large finned disc on the front, this is called the fan clutch. It is designed to allow the fan to free-spin when the engine is cool, and it locks up as the engine heats up. When they go bad, you are relying on just the airflow through the radiator from driving to cool the engine. This is OK on the highway, but in stop and go traffic, is an engine killer.

The finned disc on the front of the fan is the clutch. If it is bad, your engine won't be able to properly cool.

There are several ways to test the fan clutch. They should be tested at three intervals – fully cold, warming up, and fully hot. Please use your best judgment when attempting any tests, it is best to consult a professional.

4.  Thermostat/Radiator Cap

If your thermostat is stuck open or closed, then the cooling system cannot properly function. Overheating can be caused by a thermostat that is stuck closed, not allowing the water to flow into the radiator. If it is open, then the coolant is constantly flowing, where the engine takes longer to heat up. This can lead to overheating as well, as the coolant doesn’t have time to transfer much heat to the radiator. The thermostat can be tested by removing it from the engine and placing it in a pot of boiling water. If it opens, it is good. If it is stuck open or does not open, replace it.

The radiator cap is also a functional component. You can buy a tester or have your local NAPA AutoCare Center test it for you.

5.  Temperature Gauge

Your only warning while driving is the instrument panel, if you have an actual engine temperature gauge, make sure it is working. You can test the gauge by using an infrared thermometer (available at any NAPA AUTO PARTS store), and verify the temp of the engine block (typically at the water neck, where the upper radiator hose is connected). It should be close to the same temperature. If It is off by more than 10 degrees, get it checked out.

6.  Belts

There are two types of accessory drive belts; V and serpentine. Most newer cars use serpentine belts, which use a single belt that wraps around all of the engine’s accessories to drive them. These belts last a long time, but when they go bad, everything stops. Look for frayed edges, chunks missing or cracked ribs. If the belt is loose, you could need a tensioner pulley. If you have any concerns or not sure what to look for, swing by a NAPA AUTO PARTS store for help. V-belts use multiple belts to drive the accessories. If one breaks, the others are still working, but that may not be helpful. Look for frayed edges, rolled belts (flipped over), and loose fitting belts. All belts should not flex more than a 1/4”.

Serpentine belts don't make much fuss until they break. Make sure you check the belts regularly.

7.  Hoses

Bulging or cracked hoses are at the end of their life span. Don’t wait to replace them when they fail, this is a great way to ruin your engine. Check the radiator hoses (there are 2), the heater hoses (also 2 in most vehicles), and some newer cars have steam lines that connect to the radiator with a smaller rubber hose, check that one too.

The classic pinch test can tell you a lot about the condition of the hose. If it is mushy soft, the lining is breaking down and ripe for bursting

Electrical System

The electrical system can also face many hot-weather gremlins that only seem to show up when it is warm outside. Here are a few to watch out for.

8.  Battery/Alternator

Batteries don't just die in the winter, the summer puts a severe strain on the vehicle's charging system.

Road trips can be no fun at all if the car won’t start. Hot weather can kill a weak battery, especially if it is low on water (See our Battery 101 guide for more information on batteries), so check your water if you have a fillable flooded battery. Now is a good time to check those battery connections as well. Any corrosion should be cleaned off with a terminal brush. It is a good idea to add some anti-corrosion gel or pads to each post as well.

The electrical system gets worked pretty hard in the summertime; make sure the alternator is up to the task. Bring your car to any NAPA Auto Parts store or NAPA AutoCare Center for a quick charging system test. Doubles check the terminals on your alternator as well.

9.  Air Conditioning

Air conditioning could be the greatest invention next to the self-canceling turn signal, but if you neglect the maintenance, your road trip could leave you soaked in sweat. An annual AC servicing is a good idea to make sure your refrigerant level is optimum and that the oils inside the unit are keeping everything lubed and happy. Don’t forget to change your cabin/fresh air filter, check your vehicle’s manual for its location.

A classic summer failure is the AC system.

10.  Ignition

Sneaky little gremlins love to lurk inside your vehicle’s ignition system, waiting for a nice hot day to come out and play. If your car has lost power, stutters, and stumbles on hot days, you may have a weak ignition component in the process of failing. Cold temperatures can mask these issues such as bad solder joints and corroded internal wires, because the metals contract when it is cold, completing the connection. When things warm up, however, everything expands, opening up the circuit, and causing intermittent electrical failure. If you have an issue like this, you might want to make an appointment with your local NAPA AutoCare Center for a check-up.

Before you head out into the great wide open, be sure to check these areas on your vehicle. Not only can a little preventative maintenance save your road trip, but also your wallet.

Check out all the maintenance parts available on NAPA Online or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on summertime electrical failure, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.


Jefferson Bryant View All

A life-long gearhead, Jefferson Bryant spends more time in the shop than anywhere else. His career began in the car audio industry as a shop manager, eventually working his way into a position at Rockford Fosgate as a product designer. In 2003, he began writing tech articles for magazines, and has been working as an automotive journalist ever since. His work has been featured in Car Craft, Hot Rod, Rod & Custom, Truckin’, Mopar Muscle, and many more. Jefferson has also written 4 books and produced countless videos. Jefferson operates Red Dirt Rodz, his personal garage studio, where all of his magazine articles and tech videos are produced.

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