Lariat DRL technical question

[cfhgarza]

Does anyone know how the LED strip DRL on the Lariat headlights switch between bright and dim mode? I bought a used set and the bright mode that comes on during the day doesn't work anymore. The dim mode works though. It's a massive project to get the headlight off to check internal wiring so I'm looking for insight before I do.

If anyone has pictures of the LED board connections inside that would be a big help

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[P. A. Schilke]

Does anyone know how the LED strip DRL on the Lariat headlights switch between bright and dim mode? I bought a used set and the bright mode that comes on during the day doesn't work anymore. The dim mode works though. It's a massive project to get the headlight off to check internal wiring so I'm looking for insight before I do.

If anyone has pictures of the LED board connections inside that would be a big help

Hi Cfharza,

Hmmmm. Interesting as I though DLR switched off at night with headlights on at night. Not aware of bright and dim for the lights.... Sorry, I am of no help to answer your question but interested to see comments from those folks that did such an install...

Best,
Phil

 

[cfhgarza]

Going by this wire diagram I think the "dim" mode is turned on by the "parking light" wire and the "bright" mode is turned on by the "DRL wire.

I pulled the dust cap off the bottom and stuck my phone in there but it's almost impossible to get a good picture. I couldn't see a broken wire but it's hard to tell. Going to pull out the multimeter tomorrow and see if #6 has power.

 

[cfhgarza]

Pretty sure I found the problem. Wire that matches up with DRL on the above diagram is pinched inside the headlight. Wires on this little harness match up to the truck harness blue=DRL & brown=parking lamp

 

[cfhgarza]

That harness can bee accessed through this grey cap on the bottom of the headlight. It plugs into a small PCB along with another harness that I assume controls the low/high beams.

 

[cfhgarza]

Quick update. I did a continuity test that punched wire and it was good no matter how I bent it. I set my phone up to record and put the truck in drive. The DRL comes on for a split second then shuts offs everytime. I'm not sure what the problem is at this point ??‍ Probably undo all my Forscan changes and start fresh.

 

[kemwm38]

Going by this wire diagram I think the "dim" mode is turned on by the "parking light" wire and the "bright" mode is turned on by the "DRL wire.

I pulled the dust cap off the bottom and stuck my phone in there but it's almost impossible to get a good picture. I couldn't see a broken wire but it's hard to tell. Going to pull out the multimeter tomorrow and see if #6 has power.

Need a little help. The left side drl on my Lariat stopped working. I believe the # 6 pin and wire is cut when power for amps went thru grommet. Where or what module under dash is the other end of that wire so I can verify that’s the issue.
thanks

 

[cfhgarza]

Need a little help. The left side drl on my Lariat stopped working. I believe the # 6 pin and wire is cut when power for amps went thru grommet. Where or what module under dash is the other end of that wire so I can verify that’s the issue.
thanks

Im pretty sure it goes into the BCM since that's where headlight changes are made in Forscan. If you use a code reader it will should tell you if the DRL is shorted

 

[airline tech]

Goes to BCM, Pin 40 on connector C2280c, keep in mind that the BCM provides internal circuit protection (FET) for the individual exterior lights. You might need to do a BCM reset
C2280c - is the top middle connector on the BCM above the IPC Fuse box by your left knee

With Meter:

Note: To check DRL, place truck in (Neutral) and SET parking brake, DRL will not power in park

Pin 6 to Body Ground (voltage) this will check if you have power to connector
Pin 6 to Pin 4 (voltage) (This will ck ground circuit) wiring (Pin 4 is the ground pin for DRL)

 

[kemwm38]

Im pretty sure it goes into the BCM since that's where headlight changes are made in Forscan. If you use a code reader it will should tell you if the DRL is shorted

Appreciate help. Don’t have Forscan though. Would regular diagnostic reader pick that fault up if it’s there ?

 

[airline tech]

Appreciate help. Don’t have Forscan though. Would regular diagnostic reader pick that fault up if it’s there ?

A scanner will do the same, but it has to be capable of reading (B) Body and (U) Communication codes - most lower end scanners only read (P) Powertrain codes

 

[airline tech]

If you don't have Scanner or Forscan, you may try pulling Fuse 62 @ the Battery Junction Box, this 50 Amp fuse feeds power to the Left side, this may reset (if it is internally tripped) It's basically a virtual CB it automatically resets itself until it reaches a certain number of short circuit counts then it requires a BCM reset with scanner because it permanently disables the output power feed to the circuit to protect the BCM itself. but I would think that pulling the fuse for a few minutes would do the same. Ref the Headlight diagram I attached (Pg 1) for the Fuse and follow it to page 2
I would only worry about this if you confirm broken wire and repair it and it still does not work due to (FET) protection
FYI, (B) and (U) failure codes do not generally trip the Check Eng light like the (P) codes do, they can only be read with Scan Tool or Software as they do not affect drivability
With the DRL, not working you should see a specific (B) code to narrow down troubleshooting

 

[maxbottomtime]

Goes to BCM, Pin 40 on connector C2280c, keep in mind that the BCM provides internal circuit protection (FET) for the individual exterior lights. You might need to do a BCM reset
C2280c - is the top middle connector on the BCM above the IPC Fuse box by your left knee

With Meter:

Note: To check DRL, place truck in (Neutral) and SET parking brake, DRL will not power in park

Pin 6 to Body Ground (voltage) this will check if you have power to connector
Pin 6 to Pin 4 (voltage) (This will ck ground circuit) wiring (Pin 4 is the ground pin for DRL)

Interesting on testing DRL. Do they run by default when lows are on when in auto? I was testing default wiring with aftermarkets vs separate harness and getting nothing out of the stock wiring but maybe not putting it in neutral was my flaw. It was also so dim that lows were staying on.

 

[airline tech]

Interesting on testing DRL. Do they run by default when lows are on when in auto? I was testing default wiring with aftermarkets vs separate harness and getting nothing out of the stock wiring but maybe not putting it in neutral was my flaw. It was also so dim that lows were staying on.

Halogen and LED operate slightly different.
For Halo - DRL (Low Beams) @ Reduced Power (Intensity) in Auto, unless it's dark enough for Headlight's to be commanded on then it switches to Full Power
DRL will activate when gear is in ANY position other than park, I just used neutral for safety purpose. But DRL will not activate in PARK
Note: This is for US based Rangers only (Configurable) Canada they operate differently (Conventional) (Canada requirements are more stringent)

This is from my Halo to LED Swap, operational check
For LED:
Operational Check:

1. LED Strip - On and Bright
a. With Headlight switch in Auto (Daylight) - So DRL Mode

2. LED Strip - On and Dim
a. Headlight switch in (Headlight) and (Auto - Nighttime)
b. Headlight Switch in Park Lights
c. Activation of Entry / Exit Lights along with Park Lights, Bed Lights, Puddle Lights, Door Locks Activation Etc.








see description and ops attached

 

[maxbottomtime]

Halogen and LED operate slightly different.
For Halo - DRL (Low Beams) @ Reduced Power (Intensity) in Auto, unless it's dark enough for Headlight's to be commanded on then it switches to Full Power
DRL will activate when gear is in ANY position other than park, I just used neutral for safety purpose. But DRL will not activate in PARK
Note: This is for US based Rangers only (Configurable) Canada they operate differently (Conventional) (Canada requirements are more stringent)

This is from my Halo to LED Swap, operational check
For LED:
Operational Check:

1. LED Strip - On and Bright
a. With Headlight switch in Auto (Daylight) - So DRL Mode

2. LED Strip - On and Dim
a. Headlight switch in (Headlight) and (Auto - Nighttime)
b. Headlight Switch in Park Lights
c. Activation of Entry / Exit Lights along with Park Lights, Bed Lights, Puddle Lights, Door Locks Activation Etc.








see description and ops attached

Thanks! Is the lariat configurable or conventional? Wondering if I can play with it this evening to test in the dark or if it’s the auto lamps only (when low beams are off).

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