Daytime Running Lights (DRL) Question

[dosco]

I am interested in shutting off my DRLs on my '99 Camry. I know that the FE impact will be neglible, but stacking all the nickels will help save a buck, if you know what I mean. Plus, they kind of piss me off in that I can't signal to truckers who are trying to change lanes (instead I have to flash my highbeams).

I have looked in the Haynes manual and noted that there is a 5A circuit breaker for the DRL part of the headlight circuit.

Problem is I can't find the damn thing. Anybody have an idea of where it might be? I have looked in the 2 breaker boxes in the engine compartment, and removed the left kickplate (on the driver's side).

Any help would be appreciated.

[GasSavers_JoeBob]

Actually, I'd leave them be. They do make the car more visible...especially nice on two-lane roads. I often turn on my lights when on a two lane road...rather use a slight bit more electricity than get run over. My only fear is that I might get home and walk away from the car with the lights on. Motorcycles have been required to have headlights on when ridden for over 30 years now.

[bzipitidoo]

I was thinking maybe the best solution is go to LEDs. But, are there any LED lights suitable for this application? I don't know of any. LEDs seem best in niches, where a single color is desired and it doesn't have to be super bright. I know Autozone has LED replacements for pretty much all automotive lights except the headlights.

[rvanengen]

If the headlight housing allows it, you could just get an LED lightbulb and drill a hole, and just wire the DRL circuit to it, and leave the rest undisturbed???

[GasSavers_BEEF]

I think you would save more money by doing a warm air intake (WAI). you could also get a scangauge to see what is making a difference and what isn't. they are a little expensive $160-$170. there are many ways to save MPG that don't take away from visibility. if anything, make you more visible.

the WAI can be as simple as drilling holes in your air box and plugging the original inlet of the box. a little tape and a drill bit. instantly better MPG.

[rvanengen]

Although, if you are worried about the draw of DRLs then just turn off the radio during the daytime. ;-)

[Lug_Nut]

When my radio draws 90 watts, then I'll worry.

DRL circuits using the headlight filamants are powering what are normally 55 watt each electrical consumers. The reduced lumen output to about 80% of full power is the result of cutting the voltage at the lights by about 10% (wattage being reduced with the square of the cut in voltage.)
Your 110W lights are using about 90W in DRL mode.
But.... that reduction in voltage at the lamp socket is usually produced from a resistance wire that adds resistance, that is electrical consumption, too.
90 watts is about 1/8 of a hp (90/746). The alternator has to produce at minimum this amount of power to prevent battery depletion IF the conversion efficiency from mechanical to electrical is 100%.
At steady state speeds car x might require 12 hp to continue moving, no climbing, no accelerating, just to push air aside. That's enough for most to maintain 50~60 mph. The DRL are increasing fuel consumption by 10% to add that .12 hp they use. (correction: 1% of 12 hp)
At steady 30~45 mph when hp requirements for steady state operation might be 6 hp, those DRL are now adding 20% to the load. (correction: 2% of 6 hp)

DRL are useless in stop and go city driving. I know there's a car behind me. There are no passing areas where I need to alert the innatentive oncoming driver to not pull out to pass.
DRL are useless on divided highways. There are no oncoming vehicles. Closing rates of traffic approaching from behind leaves sufficient time for me to become aware of their presence long before their lights might be a notice of last resort.
DRL have a purpose in far northern (or southern) latitudes with long hours of dawn and dusk due to low sun angles, where sparsely settled, with long flat stretches of single lane road, providing opportunity for passing at high closing speed in proximity to oncoming traffic.
That doesn't happen where I live.
I don't run my wipers when it's sunny. I don't burn my headlights when it's sunny either.
However, There is a way to implement DRL sensibly (my definition of 'sensibly', anyway). The use of 5~10 watt dedicated bulbs can produce as identifiable a sign of presense of a vehicle as focused, high beams used as DRL.
I have just the setup RVanEngen mentions on the Camel II, but I havent wired up an equivalent on the Turdle yet (but its DRL are defeated).

[rvanengen]

I might be really confused, but isn't 90W / 4476W = 2% not 20%??

I agree...DRL's are a generally useless feature for most people in most driving conditions. My personal experience is that if someone isn't going to notice a vehicle, they are just not going to notice it. For example...conceptually, it is kinda hard to miss noticing a loud freight train, yet people do...but I guess if they put DRL's on them, we would all be safe?

On the mustang, at about 1/4 power, I am using 90W based on the published specs for the radio...although I don't usually play it quite that loud.

Originally Posted by Lug_Nut

When my radio draws 90 watts, then I'll worry.

DRL circuits using the headlight filamants are powering what are normally 55 watt each electrical consumers. The reduced lumen output to about 80% of full power is the result of cutting the voltage at the lights by about 10% (wattage being reduced with the square of the cut in voltage.)
Your 110W lights are using about 90W in DRL mode.
But.... that reduction in voltage at the lamp socket is usually produced from a resistance wire that adds resistance, that is electrical consumption, too.
90 watts is about 1/8 of a hp (90/746). The alternator has to produce at minimum this amount of power to prevent battery depletion IF the conversion efficiency from mechanical to electrical is 100%.
At steady state speeds car x might require 12 hp to continue moving, no climbing, no accelerating, just to push air aside. That's enough for most to maintain 50~60 mph. The DRL are increasing fuel consumption by 10% to add that .12 hp they use.
At steady 30~45 mph when hp requirements for steady state operation might be 6 hp, those DRL are now adding 20% to the load.

DRL are useless in stop and go city driving. I know there's a car behind me. There are no passing areas where I need to alert the innatentive oncoming driver to not pull out to pass.
DRL are useless on divided highways. There are no oncoming vehicles. Closing rates of traffic approaching from behind leaves sufficient time for me to become aware of their presence long before their lights might be a notice of last resort.
DRL have a purpose in far northern (or southern) latitudes with long hours of dawn and dusk due to low sun angles, where sparsely settled, with long flat stretches of single lane road, providing opportunity for passing at high closing speed in proximity to oncoming traffic.
That doesn't happen where I live.
I don't run my wipers when it's sunny. I don't burn my headlights when it's sunny either.
However, There is a way to implement DRL sensibly (my definition of 'sensibly', anyway). The use of 5~10 watt dedicated bulbs can produce as identifiable a sign of presense of a vehicle as focused, high beams used as DRL.
I have just the setup RVanEngen mentions on the Camel II, but I havent wired up an equivalent on the Turdle yet (but its DRL are defeated).

[dosco]

UPDATE:
After some dredging of the Toyotanation forums, I found the answer.

Disconnect the DRL resistor in the engine compartment.

Piece of cake, DRLs are now disabled. Should I want to reactivate them (I doubt it) then all I have to do is reconnect the plug.

[baddog671]

Well, if your car is anything like my Metro was, just pull your parking brake up to the first notch. That will be enough to turn all the lights off but not enough to tighten the back brakes since there is some slack in the brake cables. Check it out, yours might be the same way. If you want, you can also loosen the cables just alittle aswell...