"Who's the mechanic around here?"
The gruffness of the voice brought Gus Wilson's head around with a snap.
A large sedan had rolled to a stop in the Model Garage driveway, "I am," he
replied walking toward it.
"I hope you're better
than the rest of them around here," grumbled the driver as he stepped to the
ground. "I'll bet I've had this car to four garages in the last two
weeks."
"What seems to be the
trouble?" inquired Gus courteously.
"If I knew I wouldn't be
here," replied the driver. "But I do know that my headlight bulbs and
tail light burn out as fast as I put them in."
Gus walked around to the
front of the car and patted the headlamps. "Burn out while you're
driving?" he asked casually.
"Yeah, that's what makes
it bad. I'll be breezing along when all of a sudden they'll flare up
and go out. The thing that gets me is that new bulbs always light when
I put them in. That doesn't seem right."
Gus slid into the
driver's seat and ran his hand over the rear of the instrument panel.
Evidently satisfied with what he found, he pulled up the seat cushion and
centered his attention on the battery.
The owner ventured a
suggestion. "Do you suppose the generator has anything to do with it?"
"I'll say it has," was
Gus's abrupt reply, "But not the way you think. Take a look at this."
He held up the frayed end
of one of the battery cables. "Your battery ground wire," he
announced. "Your battery looks like it's been loose for some time and
in joggling around it's gradually broken the wire in two."
"Then, how come the car
started?" demanded the man.
"That's the funny thing
about it," said Gus. "As long as the battery stayed still, the two
ends of the wire most likely rested against each other and closed the
circuit. But every time you hit a big bump, the rebound of the springs
tossed the battery up in the air, pulled the two wires apart, and opened the
circuit. When she settled back in place again the two wires came
together and closed the circuit but if you had the lights on at the time,
the damage was done."
The customer looked
puzzled. "But I still don't see how a broken battery wire can blow out
lights," he argued.
"Maybe I can show you"
Gus said as he picked up a short twig and drew a rough picture of the
battery circuit in the gravel that bordered the driveway.
"In the first place the
generator is connected to the battery, and as long as it stays connected,
its voltage can't get any greater than the battery voltage. The
current flowing through the battery won't let it. Now, suppose we
break the ground connection to the battery," Gus suggested as he smoothed
over the gravel to form a break in the line. "That cuts the battery
out of the circuit, the generator voltage skyrockets and poof go your
lights.
"As a matter of fact, a
loose, dirty connection or a partly broken wire will cause the same trouble.
Anything that puts a lot of resistance into the charging circuit will let
the generator voltage build up too high. Then, if your lights are on
they'll blow out.
"I had a case last winter
that showed me what a little resistance in the battery circuit can do.
I had just put new headlights bulbs in a customer's car. The next day
he came in and said that the new bulbs had burned out the night before.
Since I had regulated the generator earlier in the winter, I knew that the
charging rate wasn't too high so I had to look somewhere else for the
trouble.
"It almost had me stumped
until I thought of the battery. It turned out that because of the cold
weather, the internal resistance of the battery got a little higher than
usual and added just enough resistance to the circuit to shoot the generator
voltage up and blow the lights."
As the gray-haired
mechanic worked over the battery, replacing the broken wire with a new one,
his customer, less grumpy than when he arrived watched with interest.
"It seems to me," he
said, "that manufacturers should supply their cars with some sort of
emergency light that could be used when your driving lights burn out.
I was in a tight spot the other night. A pitch black road, no lights,
and no room to get off the road. I expected to be smashed into any
minute."
"Why didn't you turn on
the dome light?" asked Gus as he grasped a connecting lug firmly between the
jaws of his pliers. "There's no reason why that should have burned
out. It wasn't on when your headlights blew."
"Gosh, I never though of
it," the man replied sheepishly.
"There are three things
you should do if your lights blow while you're driving," Gus said.
"First, jam on your brakes and guide yourself by watching the sky line or
the edge of the road until you come to a stop. Second, get as far off
the road as you can. And third, switch on your dome light for a danger
signal to the rest of the drivers on the road."
"By the way," interrupted
the man. "Before I forget it, when you put new bulbs in those
headlights will you see if you can do anything to them to make them
brighter. Even with new lamps, they seem to be awfully dull."
"It's no wonder," said
Gus when he had lifted off the headlight lenses. "Look at those
reflectors. They're so dirty it's just luck that you got any light.
Why don't you clean them now and then?"
"Thought you weren't
supposed to touch them," replied the man.
"You're not supposed to
touch them with your fingers," agreed Gus. "But that doesn't stop you
from using a piece of cotton or a soft cloth. A trick that I find
works well to dip an old handkerchief in alcohol and then in lamp black.
The combination makes a swell cleaner and polish. Don't rub the
reflectors too hard, just enough to bring back some of the original silver
finish. Of course, if they're too far gone, you can have them
re-silvered in almost any large city.
"And while we're on the
subject," added Gus, holding up one of the lens holders, "polishing won't do
much good unless you renew these lens gaskets in the rims. They're
pretty badly rotted and aren't much help in keeping out the dirt and
moisture."
"How about focusing the
lights? Would that do any good?"
"Not these headlights.
They're focused already - pre focused they call them. All the newer
cars have them. The only adjustment they'll ever need is a little
aiming.
"You can test that by
drawing a chalk line on the back wall of your garage, making it parallel to
the floor and on a level with the centers of your headlights. Then,
back your car out on the driveway so that the headlights are about
twenty-five feet from the wall and turn on your driving lights. The
upper edge of the bright beam shouldn't go much above the line. If it
does, shield first one light and then the other to find out which one is out
of whack and then re-aim it by adjusting the aiming screw or clamp under the
headlight.
"If you will point some
sort of guide line on your driveway to tell you when your headlights are
just about twenty-five feet from the wall, you can test your lights every
time you drive into the garage. Just stop a minute at that spot, turn
on your driving lights, and watch where the beam comes."
"I wouldn't mind night
driving at all," remarked the car owner, "if it wasn't for the terrific
glare you get from about nine tenths of the cars on the road. My
headlights don't seem to push past the other lights al all. It's just
like driving blind."
"They're going to try out
a tricky way of eliminating glare on the roads in Germany," replied Gus.
"In the centers of the high speed roads, they're planting a long series of
hedges crossways to make a lane. Being short of planted across the
road like the leaves of a shutter, they won't cut off the view but will cut
off the glare.
"Speaking of glare,"
continued Gus as he fastened the lenses back into place, "reminds me of old
man Curtis. About a year ago, Mr. Curtis had to make a lot of long
trips in his car. On each trip, he took a small bottle of water and a
soft cloth. Every night as soon as it got dark, he'd stop his car, wet
the cloth with the water, and wash off the headlights lenses."
"Is there anything that
the average driver can do to improve his lighting equipment?" the man asked
when Gus had finished.
"Well, besides perhaps
adding a spotlight to light up the edge of the road and a couple of fender
lights, I'd say that a pilot light mounted on the instrument board and wired
into the tall-light circuit would be the most helpful. The tail lamp
is one important light the car owner can't see. A pilot, wired in
series with the tail light, will let him know the minute the tail-light bulb
fails."
END
