Thanks mate. Okay. I have not done the mod myself. I want to state
that right up front. But, after a lot of reading and digging around
the net, it has been stated that the light sensor is basically a photo
resistor. Meaning, it has a resistive value which varies according to
the incident light acting upon it. The BCM applies a voltage to it,
and by sensing the voltage drop across it, can determine the
resistance, and thus measure the light intensity. The trick, is to
disconnect the photo resistor from the circuit. Measure the
resistance across it with an ohm meter (while it is well
illuminated!). Replace into the circuit a fixed resistor of
equivalent value. Voila! The BCM "thinks" you are driving in broad
daylight ALL the time and will not automatically turn on the
headlamps. You of course, can still turn the lights on and off as you
wish via the head lamp switch. Just like the good old days.
Now, a couple of more points on this. One thing that I thought of and
have brought up to others in some forum somewhere, is that it is an
ASSUMPTION that the sensor operates this way (as a photo resistor).
There are other types of photo sensitive circuits which could be used
to a similar end. For example, the "sensor" could actually be a
photovoltaic cell, which generates a voltage based on the incident
light acting upon it. The BCM could then "measure" a voltage through
a small IC amp circuit which in turn trips a relay when the current
goes high enough. Amplifying zero is zero, the normally closed relay
would then make the headlamps illuminate. A small EMF (voltage)
coming from the sensor, if amplified, could trip the relay to an open
condition if it gets to threshold level, thus turning off the
headlamps. That is one example of how the system _might_ operate
besides the photo resistor method. When I made this point where ever
it was being discussed, I was more or less told that no no, it really
just is a simple photo resistor. Anyway, that is why I in my original
posting in here on this I chose my words ("Replace the light sensor
with a circuit that will always present the same electrical
characteristics as the sensor does during daylight.") carefully.
Another point is a twist on the mod. Rather than simply replacing the
sensor for an item with an appropriate fixed value, you incorporate a
DPDT switch that can let you engage the fixed value device or the
original sensor. This would let you have it "automated" or strictly
under manual control at the flick of a switch.
On Wed, 06 Oct 2004 13:30:10 GMT, "Tim Dolan"
"Tim Dolan" wrote:
> Please provide more details. Would you describe a wire
> that I
> can tap into?
> Tim fm Ct>
> > "Tim Dolan" wrote:
> > > Is there any way to install a switch so the headlights can
> > turned
> > > off on
> > > a 2001 Chevy Tracker?
> > > thanks, Tim fm CT
> > The daytime running lamp (DRL) control module is located beneath
> > instrument panel to the right of the steering column. The module
> > mounted to the remote control door lock receiver bracket.
> > --
> > http://www.AutoForumz.com/ This article was posted by
> authors request
> > Articles individually checked for conformance to usenet standards
> > Topic URL:
> > Visit Topic URL to contact author (reg. reqd). Report
Sorry Tim, I just saw this in the midst of all the other post. There
are 4 conditions that must be satisfied for the DRL to work on your
vehicle. Engine running, parking brake not on, headlight switch off
and light sensor showing bright. You could rig it to think the parking
brake is on but then you would get the light on the dash. Looks like
by the schematic that when these 4 conditions are met the relay is
activated and the lights come on. I think if you remove the relay they
will go off.
Looks like you just remove the 3 screw panel directly under the
steering column. Looking up to the right of the steering column and to
the left of the heater. By the diagram it looks like there is a wiring
harness that "Ys" to the left (toward the steering column) and
right (toward heater). The part going to the right (toward heater)
goes into the RKE receiver and the DRL module is mouted on top of
Sorry, Ive never actually seen it but am describing it by pictures
from the manual. I figure if you pull the module you can see if ti
does what you want. If not just put it back and rig your emergency
http://www.AutoForumz.com/ This article was posted by author's request
Articles individually checked for conformance to usenet standards
Only in the state of New York (last time I checked a couple of years back)
where the state legislature mandated by law that car insurance companies
provide discounts for DRLs. Not all insurance companies provide discounts for
DRLs on their own elsewhere since "insurance loss data" is inconclusive as to
the benefit of those devices.
| > Is there any way to install a switch so the headlights can be turned off on
| > a 2001 Chevy Tracker?
| > thanks, Tim fm CT
A number of years ago the Pennsylvania State Legislature held
hearing on a bill making DRL mandatory. The results of test
conducted by the engineering schools of several state
universities determined that DRL's created more problems than
they might correct. Among the more serious problems was causing
motorist driving in less than desirable lighting conditions when
Pa law requires headlamps (from dusk to dawn or in fog) to be
a vehicle approaching with only DRL's that can appear to be a
vehicle properly running with headlamps at a greater distance
away. The misperception of an approaching vehicles distance
could lead to accidents while passing on a two lame roads and to
drivers making unsafe left turns, in front of approaching
traffic. Another reason was that motorcycles simply 'disappear'
in a sea of DRL'S. The NHTSA came to basically the same
conclusion when GM requested DRL's be made mandatory in the US,
about a year later.
"James C. Reeves" wrote:
No matter the distance? If you ever pull into the opposing
traffic lane at dusk when there is a vehicle actually approaching
at 200 feet that you think is 500 feet away, let me know so I can
call my brother. He
has never witnessed a head-on collision. LOL
Of course you know GM disagrees :-) ...even though nearly all of their
competitors have come to the same conclusion you mention. Insurance loss data
also shows a increase number of rear-end collisions on DRL equipped vehicles
vs. non-DRL equipped ones due to some drivers not turning their lights on when
it becomes dark. The inattentive operator thinks the lights are on since most
DRLs provide a very similar visual headlight signature (or queue) to that
inattentive operator. And there are a LOT of inattentive operators!! I wonder
if that is the reason why GM now installs a ambient light sensor (a.k.a. "auto"
headlights) on even their low-end model vehicles these days.
One item I don't understand though. I wonder why Pennsylvania passed the law
that required headlamps in construction zones a couple of years back, given
these study results. Strange...isn't it? Although I've noticed that very few
people actually follow the law.
| > | > Is there any way to install a switch so the headlights can be turned
| > | > a 2001 Chevy Tracker?
| > | > thanks, Tim fm CT
The act of turning on lights gives an extra sense of awareness to numb
Of course DRL's defeat this as they are "on".
Revenue builder. Surcharges on tickets are more than the fine.
Have a friend who's wife didn't even know how to turn the lights on in a
Grand Am due to the auto lights feature.
"anything you say can & will be misquoted & used against you"
That's true, most moving violation fines in Pa are only $25.
When the EMS training fee, the CAT fund fee and the cost costs
are added driving in a construction zone with DRL's on anywhere
else when headlamps are required will cost you $138. ;)
| Have a friend who's wife didn't even know how to turn the lights on in a
| Grand Am due to the auto lights feature.
Not a uncommon issue. Several accounts of this happening submitted as public
comments to the NHTSA. Not that it matters...the NHTSA never seems to act on
anything. They sure talk allot and attend many "conventions" though.
Then what exactly was she driving beforehand? Even though there's an
auto headlight feature on a Grand Am, the manual procedure for turning
on headlights in a Grand AM is the same as any other late model car:
rotate the ring on the headlight stalk (left hand side of the steering
column) to the ON position; reverse direction to switch it back to Auto.
If she didn't know this when she drove the Grand Am, then I doubt she
knew this beforehand, or "forgot" how to drive somehow.
I reject the idea that somehow having auto headlights makes drivers shed
IQ points all of a sudden. If they're having problems and must put
their whole faith in an auto-headlight system, and then either can't or
won't determine when the car has misjudged when it should be appropriate
to turn on the headlights and do it themselves, then they simply didn't
have the skills the begin with.
Many cars have cruise control; do these same people assume the car knows
how fast it should be going when it reaches a construction or school zone?
E-mail fudged to thwart spammers.
Transpose the c's and a's in my e-mail address to reply.
I've seen many "late-model cars" that have a different method to turn
the lights on. A knob on the dash panel that you either pull or turn
to activate the headlights. Most, if not all, Buicks fall into that
category, as well as vehicles from other makes..
Headlamps, not DRL's, are required in construction areas because
of there brightness. The light reflect off the reflective red
vests required for workers under state regulations. Headlamps
make vehicles more visible to the construction workers as well,
so they do not step in front of one.
The Pa state police love DRL's. Almost daily, at dusk, one can
see Canadian drivers pulled over on I-81 for driving with DRL's,
when they should be running with
the headlamp illuminated. $138 American for the Pa treasury LOL
"James C. Reeves" wrote:
I don't know about you, but the visual "signature cue" I go by is
whether the dashboard lights are on. In the dead of night, you can bet
that if for any reason I was stupid enough not to turn on my headlights,
the fact that I can't see the gauge cluster would be a "cue" that I
...who should not be on the road, DRLs or not.
E-mail fudged to thwart spammers.
Transpose the c's and a's in my e-mail address to reply.
| James C. Reeves wrote:
| > Of course you know GM disagrees :-) ...even though nearly all of their
| > competitors have come to the same conclusion you mention. Insurance loss
| > also shows a increase number of rear-end collisions on DRL equipped
| > vs. non-DRL equipped ones due to some drivers not turning their lights on
| > it becomes dark. The inattentive operator thinks the lights are on since
| > DRLs provide a very similar visual headlight signature (or queue) to that
| > inattentive operator.
| I don't know about you, but the visual "signature cue" I go by is
| whether the dashboard lights are on. In the dead of night, you can bet
| that if for any reason I was stupid enough not to turn on my headlights,
| the fact that I can't see the gauge cluster would be a "cue" that I
| forgot something.
One would think that the dash lights should be a good indication...although
I've known people to turn the dash intensity down to almost off as a preference
(I keep them about half way dimmed)...it probably would be a problem for them
unless it was pitch black out. But remember also, you're dealing with the
general public. Some percentage of them will use the headlight "visual cue"
method, not the dash light "visual cue" method. A good reason for engineers to
use the KISS method to design (Keep It Simple Stupid) as well as keep functions
and controls across lines and manufacturers that operate to a fairly
industry-standard way is so that as people (in general, not well aware folks
such as yourself) when they move from vehicle to vehicle, the confusion factor
is minimized (and intuitive habits do the job). They used to do that..they
apparently don't any more.
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