So I recently was pulled over by the CVSE and I have a box 2 inspection to pass soon. 1 of my current deficiencies is that my daytime running lights aren't working.

It's a canadian truck and from what I have read there should be a Module near the passenger side headlight?

I'm going to look into this tonight (the truck is stored in my dads shop with no internet or cell service) and I'm hoping to have a little more information before I go.

So a few questions would be…

1) would my headlights not work at all if the module was defective/NFG? currently they work just fine.
2) are these DRL known to be defective at all? or are they relatively reliable.
3) could a cracked/broken wire keep the DRL from working but allow the headlights high/lows to keep working
4) My multifunction switch/headlight on/off switch in the cab is a little bit finicky. It seems to spin around and around infinitely and I hear a broken spring sound in it occasionally. It all works except turning on the dash lights and interior lights can be hit or miss. Can this be related in any way to the DRL issues?

If anyone could point me in the right direction it would be great. A wiring diagram would be hugely helpful that i could print before I'm away from any resources. I am a google mechanic after all I can only get so far on my own.

Truck is a 1995 crew cab long box with the 7.3L. Canadian Made as far as I'm aware.

EDIT: Problem solved. The issue was my headlight switch. Being that my headlights worked fine when I turned them on and off highs and lows I decided it probably wasn't the DRL module.
Pulled off the dash and found this:



The spring coil/contact had been bent right off.

So with my donor switch from auto wreckers for 5$ it was a simple swap. Of course I snapped off one tab on the quick connect, classic Robert move.😒

You can see the difference here:






So the spring coil is a rotating contact point. Mine was completely missing.

And that contact point was labeled "I" I'm assuming for ignition. Which makes sense to me being that the DRL should come on when the ignition is ON



I sure hope this helps anyone else looking for an answer to this problem.

 

This won't be much help but something to look for... When day running lights came out nobody liked them so It was common to just pull the relay for them. The lights worked but no day time lights and again not much help this was done with GM vehicles. Ford my be much different but I'd look in the relay box for a missing one. I know there's a space for a fuse or a relay out there.

 

Ok thanks I will add that to the check list. Probably just be going over everything tonight with a Multimeter.

 

On these trucks the headlights won't work if the DRL module or a jumper module(for US bound trucks) is missing. If you are in the states I'd question the need for active DRL, I don't know the state by state requirements though. That loose multi function switch sounds like it could be a contributing factor though, but is it possible it's just the **** that is worn? If not I'd say you need to replace the switch.

 

The module is definitely there. I'm currently replacing my fenders and have the grill/headlight assembly off and it's sitting right there. I'll take a closer look at it tomorrow to make sure it isn't corroding away but if the module needs to be working for the headlights to be working then I will probably start looking into the Headlight switch. Currently I have the batteries out so this will be ongoing. Still keeping my eyes out for a headlights DRL wiring diagram.

As I currently understand it with the ignition in the on position low voltage goes through the module to the headlights but when the headlight switch is turned on full power goes through it? Or does it go on its own direct path from switch to headlights.

 

Actually now that I think of it I just assumed what I was looking at was the DRL module. Could it be possible that I'm just looking at the bypass plug unit? I assumed that would just be hard wired through. Mine is a little grey box with cooling fins on it.

 

Yes.. without something plugged in there the hi-beam indicator on the dash doesn't work.

 

Found the wiring Diagrams if this can be of any use to anyone in future searches.

Thanks to my local library system.

 

if it got fins it's the drl module.the shorting plug(jumper) just takes place of it.they are a fairly common thing to go.