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5 Common Mistakes When Adding Aftermarket Items To a Car

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Adding aftermarket gear or gadgets is something most vehicle owners do at one time or another. Some will have a shop install it, some will install it themselves, and some will have a friend do it. Some upgrades or add-ons are not a serious issue. That cell phone mount you clip to the vent is not likely to cause problems, but the one you stick on the dash can be.

Because most of the aftermarket add-ons people will put on their car are electrical (upgraded stereos, new lighting, etc), most of our list of five mistakes deal with electrical, but pay attention to the first and last items in all cases, even if the item you're adding is merely a clipboard mount for work or a pair of t-shirts to cover dingy upholstery.

#1 Damage to the Vehicle When Adding On

This may be one of the more common mistakes and often, it can go unnoticed for some time. Some mistakes, like accidentally drilling into the gas tank or A/C lines, are obvious almost immediately. Others, like weakening a joint or drilling into and compromising a body bushing, may not be as obvious right off the bat.

When drilling, cutting, or screwing into anything on your vehicle, you should know exactly what is on the other side, how much clearance you have, and be able to control the drill or cutter well enough to avoid hitting those things. A $50 add-on can become a $5,000 repair with one slip of the bit.

#2 Improper Wire Size, Lack of Fuses

Whatever you're adding, make sure that the wires being used to create its circuit and provide it with power are of the proper size. Wires that are too small get hot and fail (or worse). Wires that are too large may carry current too quickly and cause other issues. Wires are gauged for resistance and using the wrong size changes the resistance in the wiring and affects the outcome of your installation.

This brings us to another point: fuses. Every electrical device should have its own fuse. It should be of high quality, as should its holder. Rate it for the amps on the device plus 20 percent. Any more and having a fuse is pointless, any less and it will be blowing all the time when the device's input fluctuates (which they do in most automotive applications).

#3 Crimp But No Solder

You should always "crimp to save," but remember that a "crimp and solder" is made to last. Do both.

It's as simple as that. So do it. Every time.

#4 Flimsy Brackets, Bad Mounting Location

Sometimes, aftermarket add-ons have cheap mounting brackets or materials (screws, etc). If the item is of quality, its mounting should be as well. If the item is cheap and its brackets are too, it's more likely to be a disappointment or, worse, a projectile in an accident. Remember that when you add something physically to your car, no matter how inconsequential it may seem, it can potentially interfere with your car's safety equipment or become a safety hazard itself.

That CB radio you mounted under the dash might be the bee's knees, but when it snaps out of its cheap bracket and flies out to slam your knee and fractures your kneecap in a head-on collision, it's no longer cool.

#5 - Mounting Items Inside an Airbag Zone

This is a very, very common problem in today's vehicles. Most of your interior is probably an airbag zone if you have a car newer than ten years old. Airbags are great safety items, but put anything in front of them that isn't secured and that item becomes a cannonball. Put a well-secured item in front of the airbag and the airbag becomes a bomb and is now useless as a safety device.

Before you put those cool concert t-shirts over your car seats, for example, check to make sure that your car isn't equipped with side airbags that erupt from the seats rather than the pillar (this is now common). If so, you'll need to find another way to improve your car's upholstery. Airbag-compliant seat covers are an option.

Look at the safety graphics within your owner's manual or shop manual and note the airbag zones marked. Don't mount anything, even a temporary phone or memo pad holder that "sticks" on, inside that zone. Think of that zone as the "launch zone" for anything mounted within it.