Hey guys,

I have a 2003 Supercrew that does not have daytime running lights/automatic lights. However, when I start my truck, there's about a 2-5 second delay, I hear a relay click and my headlights come on even when the lights are switched to off. I pulled the dash apart. There is no sensor, relay or anything. Looked under the hood, there's no hint of anything for auto headlights or daytime running lights. I don't really care too much that the lights come on by themselves, especially in broad daylight.

Can I get some leads on what to chase down in order to get these lights to stop coming on automatically?

 

Only way the headlights can come on without the headlight switch being operated is the 'stalk' flash feature.
Usually both high and low beams come on with this operation
It's active at any time you want to use it.
Maybe a stalk related issue of some sort.
Good luck.

 

Can you elaborate on this "stalk" feature? I've never heard of that before.

 

In an 03 user manual page 45 is the flash to pass notation.
Pull the stalk lever toward the steering wheel and it turns on the headlights to high beam.
A spring loaded feature you would have to hold by hand to flash signal a passing intention to a driver ahead or get the attention of another vehicle.
It may be faulty.
Good luck.

 

Messed around with the assembly. If I pull it back, it flashes. If I push it forward the headlights change to high beam. So I don't think it is an issue with that. I went through the wiring and found that there is nothing for DRL or automatic lights installed either.

 

Did you locate/identify the relay that clicks?

It might have been "installed" just "for DRL or automatic lights"?

 

Haven't found the relay yet. I pulled the #9 fuse under the hood, and the lights still turn on by themselves.

 

Try this sequence to isolate were the issue is.
Starting from battery;
Remove fuse 8 a 30 amp.
Does the condition stop? Yes it's powered through this fuse. No it's being powered from some other source.
Put fuses 8 back in, remove fuse 16. Does condition clear? Yes it being powered through this fuse. No it's powered from another source.
Put fuse 16 back in.
Remove fuse 26. Does left high beam go out? If yes the circuit is good.
Remove fuse 28. Does Right lamp go out? If yes the circuit is good to this point.
I took you through the feeds starting from the main fuse in their order.
Somewhere in this procedure you should see a fault response that logic leads to the source area for the fault.
As a note; between main fuse 8 and fuses 16, 26 and 28 is the multifunction switch.
Also if the headlamp relay contacts burn closed they can 'back-feed' power to the multifunction switch and feed the head lights low beams both left and right through fuses 26 and 28.
In rare instants a shorted internal head lamp could cause a back-feed by a cross between high and low inputs.
To see all this look into a Haynes manual on page 12-23.
When there is a problem out of the norm you need to look at the schematic to see what the possible trouble area could be then re test to isolate the issue, then decide what the repair will be otherwise your floating in limbo.
Good luck.

 

Under the hood, fuse 8 isn't used on the supercrew. I did try to pull fuse 6 and 3. Still no change

Inside the cab, I pulled fuse 16, no change. Pulling fuse 26 and 28 did make each headlight go out. I pulled fuse 5 (which is supposed to supply power to DLR relay 1, and they still come on.

There is still distinct click noise in the cab before the lights come on. It is not coming from the fuse panel.

 

FINALLY! Figured out what it was. The previous owner installed something aftermarket...not sure what it is. Here's a couple pictures of it:





I was feeling all the relays I could find when I heard the click. Then I heard it coming from around the brake pedal area. Felt around, and there it was. Felt the click coming from it. I unplugged it, and my lights stay off now. Now I just have to figure out what this is. There's no part numbers on it, and it was just spliced into the regular wiring harness.

 

Way to go!

Wish I could help ID that little Black Box.

No chance of just asking PO?