2007 Ford Ranger - Disable Daytime Running Lights (DRL)

[jcwhidby]

I have a 2007 Ford Ranger, US built for a fleet, that has daytime running lights enabled. I have owned many Rangers through the years and this is the first time I have run into this. I want to disable the DRL function. What is the best way to do this? Can it be done with Forscan or do I need to add a relay in the low beam circuit to only allow the low beams to be on with the parking lights on? Thanks.

 

[lil_Blue_Ford]

I’m not sure on the 07, but the 98-01 trucks I know the DRL was a module that plugged in behind the front bumper and the non-DRL trucks just had a jumper plug there. That would be the easiest way to deal with it. Should be on the drivers side on the core support under the headlight behind the front bumper.

 

[2011Supercab]

The DRL module/relay is built into the Smart Junction Box, it's not serviceable or something that can be disabled.

Your only option is to get a SJB that doesn't have DRL.

 

[Curious Hound]

There should still be a way to disable it electrically. If someone can post the DRL wiring diagrams for that year model, I'd be happy to look at it.

The closest diagram I have is for 2002 Excursions and superduty trucks. On them, it could be disabled by removing a fuse or a resistor that is plugged into the harness.

 

[SenorNoob]

Electrical Diagrams — 2007 Ford Ranger 2WD V6-3.0L VIN U Service Manual ~ LEMON Manuals

Repair manual for the 2007 Ford Ranger 2WD V6-3.0L VIN U, including electrical diagrams, bolt torques, and labor times.

lemon-manuals.org.ua

It looks like you would have to modify the smart junction box itself. Or bypass that function entirely by building a jumper harness (with 10A fuse) to connect the Blue/White wire from the multifunction switch directly to the low beam power on the bulb connectors.

I wonder what effect it would have on it to get one of the plug in headlight harness relay kits that pulls power directly from the battery and uses the original light wiring to control a couple relays? What would a relay do with the DRL circuit driving it? I'm guessing either burn out the coil very quickly or just stay on...

A little thought suggests that a combination of the 2 methods above might be the best way to go.

This write up has some good pictures for working in the smart junction box area.

https://www.therangerstation.com/tech/2007-ford-ranger-fog-light-modification/#gsc.tab=0

 

[Curious Hound]

It looks like you would have to modify the smart junction box itself.

Yes. It does look that way. Dang it, Ford!

Or bypass that function entirely by building a jumper harness (with 10A fuse) to connect the Blue/White wire from the multifunction switch directly to the low beam power on the bulb connectors.

...AND delete a lot of the oruginal wiring.

I wonder what effect it would have on it to get one of the plug in headlight harness relay kits that pulls power directly from the battery and uses the original light wiring to control a couple relays? What would a relay do with the DRL circuit driving it? I'm guessing either burn out the coil very quickly or just stay on...

That depens on how low the frequency on the DRL PWM output is. It would probably work. But I would expect overheating and short life of the relay coil due to the impedance at the lower frequency. Not advisable.

A little thought suggests that a combination of the 2 methods above might be the best way to go.

It's possible. But, without a better idea of what is going on inside the SJB and the DRL, it's best to leave it alone. The diagrams you linked seem to have some inaccuracies because they show the PWM output directly linked to the steady 12v supply. That would defeat the purpose of the PWM in the DRL module. So there has to be some other switching in there that isn't shown in either section 85 (headlights) or section 97 (DRL) of the wiring diagrams. It's likely that the alerations we want would require changing the very circuit board itself.