Looked for the Forscan thread, but was only able to find the 2020 one. Apologies in advance if this is in the wrong spot.

I have a 2017 XLT with the halogen lights. Been using forscan to make some changes, and I'm trying to make it so only the front turn signals are on as the DRL. I've tried it a bunch of different ways but it seems like no matter what I do, the lower halogen beams will come on with the turn signals. The closest I've gotten is disabling the drl, and activating the parking lamps as drl, but I dont want the mirror or bed lights on..

Has anyone had any success? Digging into some wiring diagrams, it seems like the lower lights is fed from an auxiliary lamp module. Is there a way to disable the signal from the BCM to the aux lamp module for the DRL's? Also wondering if I can use the dedicated drl function that activates the pins at the BCM, then use a couple diodes to prevent backfeeding and use that to power up the front turn signals since those wires are at the same BCM plug.

 

 

 

Yep, enabling this line makes the parking lamps come on, which I don't want. Parking lights will be active not only in the front, but also the mirrors, taillights, and any trailer taillights if a trailer is plugged in.

I dont want parking lights, just the amber turn signals in the front with nothing else.

Changing the 726-50 to 08 enables the turn signals and the lower halogen headlight. I only want the turn signal on.

 

I don't think you're going to find the combo you're looking for. With a 2017 the closest that I ever came was the parking lights (amber due to switchback bulbs, but normally white in the parking light position), lower headlights and fogs. I liked it due to the contrast of the white (LED bulb) headlights and the amber parking lights. I've never been able to hit upon that combination again because I was not smart enough to write it down. It probably wouldn't work with the 2020 modules anyway.

 

Give this a try




ZooDad

Also here is the discussion thread on ForScan for 17-19
2017-19 ForScan

 

Thanks for the link

I tried that combo and got the computer to accept it, however the bottom headlights remain on. The top headlights are off, only the bottoms stay on.. Tried what seems like every combo imaginable with no luck.

 

Did some extensive digging and haven't found the solution yet. Some people have had luck with rewiring the bottom lights into the upper lights. Even setting the DRL setting to 10xx (dedicated drl with 36 and 40 pins active) still yields the bottom lights to come on. The only way I can trigger them off is to turn off the drl all together.

Found a wiring diagram for a halogen F250. It seems the problem lies with the auxiliary lamp module. Only the bottom headlights are fed thru that module. There must be something in the computer somewhere that triggers the module to be a DRL signal, since it looks like it gets a ms-can signal. No luck finding what triggers it. Looked thru all the modules and couldn't find it.

The led headlamps don't get fed thru this module at all and they're only present on the halogen trucks, and would explain why the led trucks don't have this issue.



Halogen wiring diagram

The only thing I did notice is when I changed the "DRL type" under the non as built BCM module from DRL, to DRL and position, this 726-12-01 and 02 string changed. There are other options to pick from like "stop and turn" and "dedicated and turn" but the bcm will not allow me to change it to those.

DRL selected:

DRL and turn selected:

 

Quick question, so when you disabled the drl and activated the parking lamps at that point your drl was only front amber turn signals mirror lights and taillights?

 

Yes. Any other combo that involved the DRL active, the bottom headlamp would stay on.