hid, bypass drl

Printed From: the12volt.com
Forum Name: Lights, Neon, LEDs, HIDs
Forum Discription: Under Car Lighting, Strobe Lights, Fog Lights, Headlights, HIDs, DRL, Tail Lights, Brake Lights, Dashboard Lights, WigWag, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=127988
Printed Date: April 28, 2024 at 1:12 AM

Topic: hid, bypass drl

Posted By: metal_mulisha
Subject: hid, bypass drl
Date Posted: July 20, 2011 at 3:30 PM

Hey guys, ive done several searches on the matter but not really finding the answer Im looking for.. Basically im putting a set of HID's into a Peterbilt 18wheeler. Now this truck has factory DRLs that are kinda hard wired into the system.. isnt as simple as unplugging a fuse or disconnecting the module.. The DRL module is actually built into another module.. So basically the truck is a dual sealed bulb system, individual low & high buld.. I plan to get the conversions and run an H4 bulb. Not sure wehter to get the single HID bulb, or the ones that have the HID bulb and halogen bulb on one unit.

So basically the problem is, when you release the parking brake in the truck the DRLs come on. The provide a lower amount of voltage to the low beam lights, not a full 12V. We have been experimenting with the install, but what happens, if you let the DRL engage the HID, they work fine for about 2 - 3 days then the ballast burns out I guess from the low voltage? I guess what Im trying to ask does anyone know a way to get around the DRLs or maybe if I go with the dul style bulb, run the halogen on the DRl, and then be able to engage HID but turn off DRL halogen.. trying to do this in the most simplest of ways, if anyone has any ideas, that be great thanks.

Replies:

Posted By: metal_mulisha
Date Posted: July 22, 2011 at 5:37 PM

lol, anybody???

Posted By: kazp3rr
Date Posted: November 02, 2012 at 3:34 PM

the drl's are controlled by the bcm of the vehicle (not familiar with 18 wheelers...but I'm sure it's the same)
you can use a simple relay to interupt the signal from the bcm to the lights, triggered by whatever you like

relays are your best friend in this kind of project (:
if you're still interested here let me know and I'll see what I can draw up for you

Posted By: ronemca
Date Posted: November 17, 2012 at 8:05 AM

I'm trying to re-establish contact with 'kazp3rr'...who very kindly offered his assistance with a similar issue over a week ago. Are you still on here, Sir?

And to the OP - were you able to sort this out?

Posted By: ronemca
Date Posted: March 12, 2014 at 8:35 AM

Yay - back from the great beyond! Too bad it's not with better news. posted_image

I finally had a mild enough day to crawl under the dash & have a look at what's going on with this blankety-blank switch (Pic). My inspection - coupled with my examination of some complex internal FoMoCo diagrams - revealed that when the parking brake is ON - even a click or two - the pedal depresses a small spring-loaded momentary switch. That closes the switch, which grounds the circuit...thereby extinguishing the DRL's.

Conversely, when the brake is OFF, and the pedal pops back up...the pressure on the switch is released and the DRL's are activated.

So - bypassing the switch (jumping/shorting the two wires) will artificially create a "BRAKE = ON" environment for the SJB...and the DRL's will no longer activate automatically. (Yes - the indicator light will illuminate on the cluster, but I can live with that.)

And it worked exactly like that. I have full (manual) control over the parking lights & the headlights. posted_image

BUT...

I forgot about the damned reminder chime!!! posted_image

As soon as I move the vehicle the chime starts dinging to remind me that I have left the parking brake on! As long as I am moving, it rings/stops/rings/stops at 30-second intervals. I think it abandons its duties after about five minutes, but I have not proven this with certainty...mostly because five-ish minutes is a surprisingly long time to tolerate that infernal dinging!

So I pulled apart my twisted ends and restored things to default operation until I decide/discover what to do next. Damn! I thought I had won this battle!

The adventure continues.

Posted By: kazp3rr
Date Posted: March 13, 2014 at 1:38 AM

Hey bro, sorry about going MIA on you. Yea, I'd have advised against the wiring into the parking brake or that very reason lol. I still stand by my original recommendation. Trace down the wire that the drl's are directly controlled by, and run it to a N.O. relay. That way you can always flip a toggle switch and have fully operational drl's (inspection time etc)
There should be a way, did you ever get hands on the schematics?
And to the OP, you still out there?

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2015 F150 XLT

Posted By: ronemca
Date Posted: March 14, 2014 at 10:08 PM

In fact I have extremely detailed schematics from FoMoCo...but I am in over my head trying to decipher them (hint hint) I * really really * want to do this.

Posted By: kazp3rr
Date Posted: March 15, 2014 at 1:40 AM

gonna pm you my contact info, since I don't get on here that often.

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2015 F150 XLT