wales@ucla-cs.UUCP (01/02/85)
I recently bought fog lights for my '84 Honda Accord and installed them
myself. Honda's installation instructions describe how to aim the fog
lights -- but, as it turns out, the instructions are COMPLETELY WRONG,
and following them could create a traffic hazard and get you a ticket.
Any '84 Honda Accord owner with fog lights should probably check the
aiming of these lights -- even if the lights were installed by a dealer
or came on the car when originally purchased. (I haven't yet been able
to check whether Honda sent out supplementary info to their dealers to
correct the mistake in the installation instructions -- but I wouldn't
bet on it.)
Here's what's wrong:
The instructions that came with my lights said to shine both the fog
lights and the low-beams on a wall or screen 25 feet in front of the
car -- and then to aim the fog lights so that the top edge of their
high-intensity zone is 4 inches below the horizontal centerline of
the headlight beams.
However, since the fog lights on an Accord are mounted below the
bumper (and are, by actual measurement, 12 inches below the head-
lights), following Honda's instructions will cause the fog lights to
point at an UPWARD angle.
Not only will such mis-aiming partially defeat the legitimate pur-
pose of the fog lights, but it will also cause the lights to glare
VERY brightly into the eyes of other drivers.
Here's what should be done:
According to the California Vehicle Code (I wrote down the section
number, but then misplaced my notes), the fog lights are supposed to
be aimed so that the top edge of the high-intensity zone -- measured
on a screen 25 feet in front of the car -- is 4 inches below the
LEVEL OF THE CENTERS OF THE LIGHTS THEMSELVES.
The centers of my fog lights are 12.5 inches above ground level;
hence, the top of the high-intensity zone on the screen should be
8.5 inches off the ground.
I can't speak for the laws in states or provinces other than Cali-
fornia, but I would assume California's law w/r/t fog light aiming
is typical. Honda's instructions are certainly wrong everywhere,
needless to say.
I'm going to write Honda to point out this problem (with a copy to the
California Department of Motor Vehicles, to make sure that Honda takes
notice and corrects the error).
Comments are welcome -- but, please, no flames regarding the pro's and
con's of fog lights in general.
--
Rich Wales
UCLA Computer Science Department
3531 Boelter Hall // Los Angeles, CA 90024 // (213) 825-5683
ARPA: wales@UCLA-LOCUS.ARPA
UUCP: ...!{cepu,ihnp4,trwspp,ucbvax}!ucla-cs!wales