INSTALLATION KNOWLEDGE & TECHNIQUE
Section 6 Shop Safety
You’ve probably heard the popular slogan, “Safety First.”
This is especially true for installers – particularly when you have three jobs wait-ing…and it’s four o’clock on Friday afternoon!
In the real world, safety often comes last.
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It’s important to stress, however, that the installation bay offers a variety of haz-ards. Electric shock, hazardous chemicals, and sharp tools are just a few.
The Occupational Safety and Health Administration (OSHA) is the government agency that regulates on-the-job safety.
■ OSHA requires that all employers maintain a safe and healthy work envi-ronment.
■ The Code of Federal Regulations (CFR) lists safety and health standards, and employers face stiff fines if these standards are not followed.
While the shop owner is ultimately responsible for accidents, safety begins with the individual. Therefore, a properly maintained attitude is your most important
“tool” to help promote shop efficiency and safety.
SAFETY PRACTICES
The installation bay is no place for playing games or fooling around. Protect your-self from horseplay that can lead to accidents, and always wear the appropriate gear before you begin a job. You will only lose that right eye or index finger once, and after the fact is too late to start being careful.
Eyes:
When using power tools – such as power nibblers, routers, jig/sabre saws, radial arm saws, Dremel tools, etc. – Always wear safety glasses or goggles.
■ Some installers think wearing safety glasses makes them look “un-cool.”
However, looking “cool” does little good if you’re permanently blinded by flying wood or metal chips.
Ears:
OSHA has specific regulations for hearing protection. Listening to a sound system
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Always wear safety glasses or goggles.✍
OSHA has specific regu-lations for hearing protection.Listening to a sound system playing at 100 dBA SPL for two hours will start to cause
hearing damage. NOISE EXPOSURE CHART
Sound Level (dBA) Maximum 24-Hour Exposure Occupational Nonoccupational
playing at 100 dBA SPL for two hours will start to cause hearing damage.
■ If you’re constantly exposed to high decibel sound, wear earplugs or ear protection.
Respiratory:
When working around sawdust or other airborne material, always wear a dust mask. Fiberglass and particle board are especially hazardous. The glue in particle board is toxic, and fiberglass can cause severe skin irritation and lung damage if it is inhaled.
When working with lead based solder, it should never be heated in excess of 1000°F, at this point the solder becomes vaporized and emits hazardous vapor-ized lead oxide. Be sure to check the soldering iron temperature rating before sol-dering. Always solder in a well ventilated area.
Hands:
Use gloves – full or partial – to protect your fingers and skin from being torn, cut, or burned.
■ Be particularly careful when working with large power tools.
SAFETY AROUND BATTERIES
By their very nature, batteries present a number of hazards. Chemical reactions taking place inside of batteries generate flammable vapors. Therefore, never strike a match, a lighter, or anything that creates a spark or flame near a battery.
Although most modern batteries are sealed, older batteries still have vent caps which need to be opened to be filled with distilled water.
■ While working around battery fluids, take extreme care not to come in contact with the main chemical ingredient, sulfuric acid.
■ Sulfuric acid is highly volatile, and will burn through clothing and skin, not to mention what can happen if it comes in contact with eyes.
SAFE TOOL USE
Make sure you know how to properly handle any tool – powered or not – before you pick it up.
■ If improperly used, the air chisel is the most dangerous tool in the shop.
■ Just the noise generated by this tool is enough to damage hearing if protection is not used.
■ If proper precautions are not taken, a window can shatter in a door
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When working around sawdust or other airborne material, always wear a dust mask.✍
Use gloves – full or partial – to protect your fingers and skin from being torn, cut, or burned.✍
Never strike a match, a lighter, or anything that creates a spark or flame near a battery.✍
Sulfuric acid is highly volatile, and will burn through clothing and skin, not to mention what can happen if it comes in contact with eyes.and the rear window seal can have its integrity diminished due to the vibrations caused by an improperly used air chisel on a rear deck.
Dikes, long nose pliers, and crimp tools should have insulated handles.
■ These are insulated not only for your comfort in reducing blisters from crimping and cutting all day, but to insulate you from electrical shock, should you accidentally hit a live wire or battery terminal.
FIRE EXTINGUISHERS
The laws of most states, cities, and counties require any shop which is working on motor vehicles to have at least one fire extinguisher on the premises. Fines and/or possible jail sentences await those who refuse to comply with this law.
Most fire extinguishers work by removing the source of oxygen from the fire. The types of extinguishers are noted as follows:
■ Type A – for wood and paper
■ Type B – for oil and flammable liquids
■ Type C – for fires of an electrical nature
■ Halon – for all types of fires
The extinguisher best suited for a mobile electronics shop is the Halon type. Always make sure that the extinguisher is serviced at the appropriate interval, according to the tag which was affixed to it during the last inspection or recharging.
Should you be unfortunate enough to have to fight a fire:
■ Always point the nozzle on the extinguisher toward the base of the flames – not the burning material.
■ Only attempt to fight small, controllable fires.
■ If a fire looks as though it’s getting out of hand, always contact the fire department.
■ Never try to fight larger fires on your own.
■ Remember, what may “look” like a fire may be only the insulation melting off a wire, so don’t panic and reach for the fire extinguisher. The bills to pay for cleaning a vehicle's interior can easily eat into profits.
CLEANING THE SHOP
Keeping the shop clean is also a part of safety, to say nothing about professionalism.
■ A clean shop reassures the customers that they’ve made the right choice about your services.
Follow these guidelines:
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The extinguisher best suited for a mobile electron-ics shop is the Halon type.■ Floors should be swept up as often as possible.
■ Reels of cable should be put back on their racks.
■ Boxes that equipment came in should be put in the owner’s car or prop-erly recycled.
■ When cleaning up metal chips from power nibblers, or other tools, never leave them on the floor to be swept up later.
■ These chips can find their way into customers’ tires, the interior of their cars, and the bottoms of your shoes.
■ An old magnet can easily pickup stray nibbler chips to keep them from being tracked all over the shop.
■ A heavy-duty shop vac is essential in every shop.
FIRST AID
Try as we may to operate safely, the occasional accident will happen.
■ Every phone in the shop should have the number of the nearest hospital emergency room, police department, and fire department.
Every shop should have a first aid cabinet well stocked with bandages, adhesive tape, antibiotic first aid cream, eye wash, iodine, and alcohol.
■ These are available at medical supply houses and industrial supply houses.
■ The cabinet should be kept at a convenient, central location.
■ It’s advisable that one or more of your crew knows basic first aid and CPR.
Finally, because installers work with a lot of rusty metal, screws, and other unsa-vory items, you should get a tetanus shot every seven years.
Section 7
Troubleshooting Guide
OVERALL
The customer comes to you with a physical problem (scratched paint, dirty or torn interior, etc.) after the installation:
■ Review the “vehicle check-out” form with the client.
■ Show them where the damage was noted on the form prior to the installation (and that the client signed that form before work was started.)
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■ If you – or someone in your shop – did the damage, take responsi-bility and get it repaired.
The customer returns a year after the installation with a question and/or problem:
■ Refer to the job log (which should be kept on file). It should include:
■ Wire codes for installing alarms.
■ Wire colors for hooking up power supply leads and power antennas.
■ Enclosure sizes for subwoofers in specific automobiles.
■ Templates that are made for special head units, antenna, and speaker installations.
■ Information on raw-materials sourcing, product sourcing, and people to contact in case of installation problems.
NOISE PROBLEMS
The three keys to noise problems:
1 Identify 2 Isolate 3 Eliminate
How to identify the problem:
1 What are the symptoms?
2 What kind of noise is it?
3 Does the noise run through the whole system?
4 Does the noise go up and down with the volume control?
5 When did the noise start?
6 Does the noise rise and fall with engine speeds?
7 How long has it existed?
8 Is the noise affected by driving over bumps or dips?
Isolate:
Once you have identified the problem, the next step is to isolate it to determine in what stage of the circuit the problem exists.
Eliminate:
Here are some suggestions to help you eliminate various “noise” problems:
■ Check that the power and signal leads are run away from each other.
■ Is the battery lead crossing over other vehicle wiring?
■ Is your wiring next to any factory wiring harnesses?
■ Check for passive crossovers installed near factory wiring harnesses.
■ Is the power source noise-free?
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■ Does the power source have enough current-carrying capacity for the unit each wire will be powering?
■ Are the speaker wires and line--level signal leads on the opposite side of the vehicle?
■ If this can’t be done, try to keep power and signal cables as far apart from each other as possible – or a minimum of 18 inches.
■ If you have to route power and signal cables over one another, it’s best that they cross at a 90 degree angle.
■ Is power being accessed from the fuse block or directly from the battery?
■ The fuse block is typically the noisiest spot on the vehicle to access power.
■ Check that sill molding screws or rear seat framing/springs have not punctured the insulation of the power cable and shorted it to ground.
■ Is an amplifier or any other component mounted directly to the metal of the vehicle?
■ Always use an amp rack and insulate the other components from the chassis of the vehicle.
■ How are the preamps grounded?
■ Some preamp units get their B- connection directly from the inter-connect cable – inter-connecting the black wire to ground in this case caus-es an automatic ground loop.
■ Ground preamp components to one point – usually the back of the radio – if their power supply ground is separate from signal ground.
■ Do any components share a ground connection with the vehicle's acces-sory ground path?
■ If the autosound system shares a ground with a fan motor or brake light ground, it is likely that a pop or a buzz will be heard in the sys-tem whenever the fan is turned on or the brakes are applied.
■ Are you using the factory head unit power and ground wiring?
■ This wiring usually has inferior gauge and often does not go direct-ly to ground, but picks up grounds of other vehicle systems which are clustered together at one point.
■ Factory wiring typically runs in harnesses past other devices in the vehicle, which can radiate or couple noise into an audio system.
■ Try moving the location of the power cable away from such items as vehicle computers and stock wire looms.
■ If this does not help, a noise filter can be put on the power line (an
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in-line passive noise filter will always drop the voltage to the amplifier and may limit its performance.)
■ If you think a noise problem is coming in on the power cable, run a new one OUTSIDE of the vehicle, away from possible noise-producing vehicle items just to check.
■ Is it radiated noise?
■ To find the source of the noise, use a noise sniffer.
■ Make sure you find the true source of the noise because noise can sometimes come from a secondary radiator.
■ The cure may be as simple as moving the secondary radiator away from the primary radiator (i.e., moving a stock wire loom a few inches from another wire loom).
■ Most types of radiated noise cannot be eliminated, they can only be rerouted or redirected.
■ Is the antenna is the source of the noise?
■ Mounting the antenna as far away from the engine as possible will usually reduce Radio Frequency Interference (RFI).
■ With the antenna – are the rockers under the fender firmly digging into metal?
■ Noise can enter a system is if the battery is not fully charged
■ A low battery will not properly filter ripple from the output of the alternator
■ Battery problems can be caused by a number of conditions; check for:
Low water in the battery Loose or corroded battery cables Slipping belts
Dirt on the top of the battery
One dead cell with five other good cells If there is a problem with the wiring:
■ Are wires through holes that have rough metal edges?
■ Are grommets used whenever wires pass through metal boundaries?
■ Are wires getting pinched beneath seat tracks, clutch and brake pedals, etc.?
If there is a loose connection:
■ Are terminating wires soldered and then covered with heat shrink tubing?
■ Connections in the engine bay of a vehicle should be soldered.
■ When the connection is attached to the firewall, have you applied
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noncorrosive grease to the screw head?
■ Is the solder joint smooth, shiny, and concave? (It should be).
■ If using a crimp-tool, is it a secure mechanical connection?
■ When using a crimp-tool, the seam of the metal barrel (unless it is seamless) should be in the concave part of the crimper's jaws to ensure a secure mechanical connection.
■ Over time, oxidation can build up between the wire and the con-nectors (this oxidation causes a degradation in the electrical connec-tion, causing an increase in resistance, which hurts overall perfor-mance).
In a remote-controlled alarm system installation, you do have a constant +12VDC:
■ Is the system wired to the ignition switch?
■ Is the system wired directly to the battery?
Is there “alternator whine”:
■ Here’s how to check: With the audio system on and the volume turned all the way down, “rev” the engine – if the whine is heard, unplug the line inputs at the amp or crossover; if the whine goes away, you’ve more than likely got a ground loop.
■ Make sure all grounds are assembled at one point only and that amp mounting, crossover mounting, equalizer mounting, etc., are not allow-ing these components to touch ground.
■ Check for a ground loop:
■ Poor crimps can cause a ground loop.
■ Check low-level leads going from the output of a headunit to the input of a crossover or amp.
■ Noise can be caused by using inferior cable with poor shielding.
■ Do you have a “good” ground? (Metal-to-metal contact).
■ Check the alternator.
■ Measure the ground point potential back to the negative battery post and with each other.
■ Single point grounding is preferred.
If a fuse is always “blowing”:
■ Be sure the fuse meets the total amp draw and is able to handle the total amperage.
■ Remember amplifiers that run more speakers at lower impedances use more current.
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■ A speaker may be “shorted out.”
■ The input voltage to the amplifier is too low.
Is there an intermittent problem with the alarm being triggered for no apparent reason?
■ A failing car battery can cause an alarm to be triggered for no apparent reason, giving the customer the impression that the alarm is defective.
■ Loose or corroded cables can also cause a problem.
In case of a fire:
■ Point the nozzle on the extinguisher toward the base of the flames – not the burning material.
■ Only attempt to fight small, controllable fires.
■ If a fire looks as though it's getting out of hand, always contact the fire department.
■ Never try to fight larger fires on your own.
■ What may “look” like a fire may be only the insulation melting off a wire – don’t panic and reach for the fire extinguisher.
Every shop should have a first aid cabinet well stocked with bandages, adhe-sive tape, antibiotic first aid cream, eye wash, iodine, and alcohol.
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SAMPLE TEST QUESTIONS
1 Which of the following is not part of the “vehicle check-out” that is performed before starting work?
A Inspect the body.
B Inspect the trunk.
C Inspect the battery level.
D Inspect under the hood.
E Inspect the interior.
2 You should maintain a personal dress code to help you from being blamed for damage that existed before the car came into the shop.
A True B False
3 What is the general rule of thumb regarding power and signal leads?
A Always run power and signal leads next to each other.
B Depending on the installation, it’s okay to cross the battery lead.
C Run the wiring parallel to the car’s factory wiring for ease of routing.
D Run the battery power lead down the same side as the battery.
E All of the above answers are correct.
4 Ground loops are the most frequent cause of noise problems in car audio installations.
A True B False
5 When should you use wire nuts in an installation?
A Always.
B For the power lead.
C For speaker connections.
D Never.
6 How do you test for “alternator whine”?
A Turn the audio system on, turn volume all the way down, then
“rev” the engine.
B Turn the audio system off, then “rev” the engine.
C Use a noise sniffer.
D Use a Digital Multimeter.
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E All of the above techniques can be used to test for alternator whine.
7 Which of the following is the best diagnostic tool for use on a brand new car with a computer-controlled ignition, computerized climate control system and a trip computer?
A VOM (Volt-Ohm Meter).
B Test light.
C DMM (Digital MultiMeter).
D Hydrometer.
8 If you want to check the amperage draw of a component or security system brain, and the suspect component is not blowing the fuse it comes with, you should set your amperage scale on your VOM to a range above the fuse rating of the component.
A True B False
9 According to OSHA (Occupational Safety and Health Administration), what will cause hearing damage?
A Listening to a sound system playing at 90 dBA SPL for four hours.
B Listening to a sound system playing at 95 dBA SPL for three hours.
C Listening to a sound system playing at 100 dBA SPL for two hours.
D Listening to a sound system playing at 105 dBA SPL for one hour.
E Listening to a sound system playing at 110 dBA SPL for four minutes.
E Listening to a sound system playing at 110 dBA SPL for four minutes.