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DRL Mod Pics / How-to?

autumn walker

Well-Known Member
Messages
707
Location
Nova Scotia, Canada
Can someone post the DRL mod how-to? Pics would be appreciated. I assume a switch could be wired in as well so that I can toggle the "fog" lamps on / off when my headlights are on?
 

4speedfunk

Well-Known Member
Messages
4,158
Location
Tardville
Yeah...me too. My garage faces my neighbor's living room and I would like to leave my lights off (day and night) until I pull out of my driveway...so I'm not blasting them with headlight beams. I would like to take the spring out of the switch, so it doesn't re-set to AUTO. I don't mind having the AUTO function on the switch, I just wish it gave the driver control of where it stays...like a normal vehicle. I would prefer to keep it in the OFF position, so I wouldn't have to reach over and cancel it every single time I start the truck. One of the many ill-conceived, super-annoying, electrical features that chokes the H3.

My wife's 2006 Chrysler 300 has the same arrangement but, it does not have the spring that defaults to AUTO. Instead it has a detent position for AUTO just like it does for ON, OFF, and PARKING light settings, (the way it should be). This way the driver has full control over the lighting system. If you desire AUTO...just put it there, and leave it. If you desire OFF...it stays there until you change it.

I've actually considered swapping the GM switch out for the Mopar switch...they are both rotary style switches, and I don't think it would be too hard to do. You just gotta make sure you get all the corresponding wires hooked up correctly. Past experience tells me that this switch uses a single plug connection that gangs all the terminals together in one socket, so I would need to grab the Mopar socket and 6" of pigtail along with the switch. This should allow me to cut and hard splice each of the Mopar wires into the Hummer harness. It remains to be seen if this will freak-out the Hummer computer...probably not as the only difference would be that the new OFF position would now have a detent instead of a spring. I might be able to test this by starting the H3 while holding the stock switch to OFF position...to see if it causes any problems. That's essentially what the Mopar switch would be doing.

Now. How do we get rid of those auto door-locks? -LOL
 

[__--MUD--__]

Well-Known Member
Messages
125
Location
South West Michigan
Most everything on the H2 is databus controlled. Switches are not conventional switches. The fog light control knob has a single dark green wire that sends a data signal to the body control module.

If you want to manually control the fog/DRL light, in the fuse block under the hood find the DRL relay. There is a light green/black (from the BCM) and dark blue (to each fog) wire coming out of that. Cut the line from the BCM and run that to a switch. The switch will toggle the stock relay which will turn on/off power its receiving from the 10 amp DRL fuse in that same box. This completely removes any automatic/manual control from the BCM and headlight switch.
 

[__--MUD--__]

Well-Known Member
Messages
125
Location
South West Michigan
drl.JPG

Here is the diagram, study it carefully... dont just blindly go off what I said.
 

autumn walker

Well-Known Member
Messages
707
Location
Nova Scotia, Canada
[__--MUD--__];62389 said:
Cut the line from the BCM and run that to a switch.

anything to do with modifying the wires to / from the BCM scares the crap out of me.

I have seen pics where people just jump a fuse and relay in the main fuse block to keep DRLs on with headlights. I figure I could just throw a switch in between to toggle the DRLs as I please.
 

[__--MUD--__]

Well-Known Member
Messages
125
Location
South West Michigan
Yea you can do the jumper to tie them into the headlight operation, putting a switch in that jumper would give you the option of running the drl w/ the headlights. It would not give you the option to turn them off in a condition they are on by the bcm.

That light green\black is just a relay control wire, I dont believe it does anything but supplys signal power to the relay.

You could put a 3 way switch there.
1) Factory behavior, (from BCM to relay)
2) Manual on, (disconnected from bcm/ energising relay)
3) Manual off (relay signal disconnected)

If you dont like any of those options, you can completely ****can that drl fixture as its not worth a **** anyway. disconnect the stock fixtures from the harness and seal up the connector ends. Simply wire a new fixture in there, preferably controlled by a relay.

drl2.JPG
 

ReconH3

Guardian Angel
Messages
2,288
Location
Raleigh, NC
I've been very interested in disabling my DRLs. Unfortunately I'm electrically impaired and have no clue on how to go about it.
 

Pappibri

Well-Known Member
Messages
1,611
Location
Cohoctah, MI
Yeah...me too. My garage faces my neighbor's living room and I would like to leave my lights off (day and night) until I pull out of my driveway...so I'm not blasting them with headlight beams.

I like to hear about others who are respectful like that to their neighbors. Dont seem like there are many of us though... I too would like to disable that.. I dont like my lights being on during the day, and I would like to be able to run my fogs on highbeams also... But electrical scares the crap outta me also.. One wrong snip, and no trip...
 

autumn walker

Well-Known Member
Messages
707
Location
Nova Scotia, Canada
DRLs are a legal requirement here in Canada - you can get ticketed for not having them on (that's why they are automatic). Even old vehicles are required to manually switch on their headlights during the day!

I would just like the ability to switch my DRL lights on when my headlamps are on.
 
Messages
1,248
Location
New Jersey
I had mine wired so they go on only when I turn my headlights on. I hated not being able to even know if they were on, and mostly wanted all my lights to turn on at the same time. Much nicer look too
 

ReconH3

Guardian Angel
Messages
2,288
Location
Raleigh, NC
I had mine wired so they go on only when I turn my headlights on. I hated not being able to even know if they were on, and mostly wanted all my lights to turn on at the same time. Much nicer look too

Can you please explain what you did to have them wired like that?


"Ex Umbris Venimus"
 

shupe13

Probationary Member
Messages
1
Location
Pennsylvania
Can someone please tell me why my drls aren't working. I replaced the fuse and the relay and still no lights does the shifter have to be in drive before they cime on. Its frustating the shat out of me......HELP
 
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