1997ThunderbirdLXV6
PostWhore
In my series of How-To articles which nobody may need, but they're my contribution to site growth, here is information previously posted yet somewhat buried in the What [...] today thread.
My usual disclaimer: I'm not a professional, know nothing about electricity, and don't make any recommendations.
Intro
To provide some background, DRL requirements are published here:
DRLs can be white, clear incandescent, selective yellow, yellow or amber. Each DRL optically combined with a turn signal lamp must be automatically deactivated as a DRL when the turn signal lamp or hazard warning lamp is activated, and automatically reactivated as a DRL when the turn signal lamp or hazard warning lamp is deactivated.
Amber DRLs were somewhat common in the early 2000s, especially among GM and Toyota vehicles, but fell out of favor with the arrival of white LED accent lighting.
Recently, they're making somewhat of a comeback, with amber DRLs popping up on F-150, Challenger, various Kias and apparently as a popular mod on Broncos.
If you don't like DRLs, this isn't for you. If you do, the question of color presents itself. Amber looks nicer than white in my opinion. The challenge then becomes how the DRL interacts with the turn signal.
Starting Point
Most MN12s, except the very early model years, feature a total of four front sockets for 3157 type bulbs, two inboard and two outboard. All have three pin sockets, though the inboard harnesses lack the pin for the major input. Factory wiring therefore is:
The words "Major", "Minor", and "Ground" are literally written on the sockets. So you can't go wrong.
Now you have to determine which lights you want as DRLs. All four, only outboard, or only inboard. I went with only inboard (my outboard lights maintain their stock functionality).
Seen here mid-day:
Seen here at dusk:
Functionality
Some of you have seen my video on the subject. Since I'm not sure how long that'll be up, I also describe the functionality below.
Note that we're only talking about the major lead on the lights that you're using as DRLs. Everything else remains stock!
To achieve this functionality, you can either concoct a highly complicated series of relays...or use an existing module. This how-to uses a GM module from late 90s minivans of this body style:
I know, I know...
But they're easily available for cheap! The module needed is under the dash directly above the driver's left foot, and it pops right out without any tools; just cut a few inches of wires.
The Module
The module is about the size of a box of cigarettes. Note that the above picture is missing one light blue wire in the left connector; I took that pic before I realized that wire was needed.
I won't go into detail where to mount it, though I suggest putting it into the interior rather than the engine compartment.
Wiring
Going from top to bottom:
@XR7-4.6 , since you completed this mod, if you have anything to add, please do.
I hope this is useful.
My usual disclaimer: I'm not a professional, know nothing about electricity, and don't make any recommendations.
Intro
To provide some background, DRL requirements are published here:
DRLs can be white, clear incandescent, selective yellow, yellow or amber. Each DRL optically combined with a turn signal lamp must be automatically deactivated as a DRL when the turn signal lamp or hazard warning lamp is activated, and automatically reactivated as a DRL when the turn signal lamp or hazard warning lamp is deactivated.
Amber DRLs were somewhat common in the early 2000s, especially among GM and Toyota vehicles, but fell out of favor with the arrival of white LED accent lighting.
Recently, they're making somewhat of a comeback, with amber DRLs popping up on F-150, Challenger, various Kias and apparently as a popular mod on Broncos.
If you don't like DRLs, this isn't for you. If you do, the question of color presents itself. Amber looks nicer than white in my opinion. The challenge then becomes how the DRL interacts with the turn signal.
Starting Point
Most MN12s, except the very early model years, feature a total of four front sockets for 3157 type bulbs, two inboard and two outboard. All have three pin sockets, though the inboard harnesses lack the pin for the major input. Factory wiring therefore is:
- Inboard:
- Minor: parking lights
- Ground
- Outboard:
- Major: turn signal/hazard
- Minor: parking lights/side marker
- Ground
The words "Major", "Minor", and "Ground" are literally written on the sockets. So you can't go wrong.
Now you have to determine which lights you want as DRLs. All four, only outboard, or only inboard. I went with only inboard (my outboard lights maintain their stock functionality).
Seen here mid-day:
Seen here at dusk:
Functionality
Some of you have seen my video on the subject. Since I'm not sure how long that'll be up, I also describe the functionality below.
Note that we're only talking about the major lead on the lights that you're using as DRLs. Everything else remains stock!
| Ignition off; Hazard in use | Major pin gets power from turn/hazard |
| Ignition on; Headlights off; Turn/hazard not in use | Major pin gets constant power |
| Ignition on; Headlights off; Turn/hazard in use | Major pin gets power from turn/hazard; reverts to constant power after use |
| Ignition on; Headlights on | Major pin gets power from turn/hazard |
To achieve this functionality, you can either concoct a highly complicated series of relays...or use an existing module. This how-to uses a GM module from late 90s minivans of this body style:
I know, I know...
But they're easily available for cheap! The module needed is under the dash directly above the driver's left foot, and it pops right out without any tools; just cut a few inches of wires.
The Module
The module is about the size of a box of cigarettes. Note that the above picture is missing one light blue wire in the left connector; I took that pic before I realized that wire was needed.
I won't go into detail where to mount it, though I suggest putting it into the interior rather than the engine compartment.
Wiring
Going from top to bottom:
- Orange: not needed
- Orange: not needed
- Light blue: to one turn signal bulb
- Light blue/white: from one turn signal feed from MFS
- Dark blue/white: from other turn signal feed from MFS
- Dark blue: to other turn signal bulb
- Pink: Ignition feed (for DRL power)
- Light blue: Ignition feed (to fool module into thinking parking brake is released; if you wanted, you could actually wire this to turn off DRLs when parking brake is on, but why bother?)
- Brown: not needed
- Light green/black AND yellow/black: connect to each other (to fool module into thinking that ambient light sensor is installed and sun is shining; this is how GM cars without automatic lights are actually wired.)
- Black: ground
- Brown/white: not needed
- Brown: not needed
- Yellow: headlights feed
@XR7-4.6 , since you completed this mod, if you have anything to add, please do.
I hope this is useful.
