Daytime running lights (DRL) not working, relay?

dragnet

Well-known member
Dec 23, 2008
120
0
A while back my drivers side headlight blew out and took the fuse with it. Around that time my DRLs started failing as well. Intermittent at first then gone completely. As per the RAVE documentation below I've checked fuse 13 in the engine compartment and fuses 3 and 22 in the passenger compartment. I'm also attaching two pictures of my passenger fuse box in the hopes that someone can tell me which relay is the DRL relay. For our American friends who do not require DRL you're lucky, but perhaps you can tell me if your rig has the highlighted relays in it or not. I would expect you to be missing the DRL relay.

I've also attached my fuse box diagram which seems to indicate two DRL relays in the picture. RAVE does not mention two. Is it the Tyco or NEC relay I'm interested in?

Thanks.

Daylight Running Lamps Supply

The feed from fuse 13 in the engine compartment fusebox is connected to the
coil of the daylight running relay and the IDM integral with the passenger
compartment fusebox.
When the engine is started, the IDM senses, through internal circuitry, that the
engine is running and provides an earth for the daylight running relay coil. The
energised coil closes the contacts of the daylight running relay allowing the
feed from fuse 5 in the passenger compartment fusebox to pass through the
relay contacts.

Daylight Running Lamps Operation

Canadian vehicles

The feed from the daylight running relay contacts flows from the passenger
compartment fusebox and is connected to a 0.75 Ohm in-line resistor on an RU
wire. The feed from the in-line resistor is reduced to 6.7 V and reconnected to
the passenger compartment fusebox on a UY wire. The feed is connected to
fuses 3 and 22 in the passenger compartment fusebox, where it operates both
headlamp main beam bulbs at reduced power.

 
Last edited:

KyleT

Well-known member
Mar 28, 2007
6,056
2
35
Fort Worth, TEXAS
The drl relay is on the drivers side headlight harness under the air box iirc. That's where mine is and I believe 03/04 as well.
 

jafir

Well-known member
May 4, 2011
1,628
0
Northwest Arkansas
KyleT said:
The drl relay is on the drivers side headlight harness under the air box iirc. That's where mine is and I believe 03/04 as well.
That's the drl resistor. I don't believe the 03-04 have that same type of resistor. My 1999 had it though.
 

dragnet

Well-known member
Dec 23, 2008
120
0
Thanks guys,

I believe you are right jafir. The 03-04 Disco has a different setup then the previous years.

Jafir, are you saying that the piece of metal I see in the top left corner of my fuse box is the DRL relay the RAVE is mentioning?

The two turn signal relays look to be the same as the DRL relay above them. I've tried swapping each turn signal relay with the DRL relay above and have had no luck.

What is the IDM that the RAVE is mentioning? I should know what it means but the acronym escapes me. I assume the M stands for module of some type.

Thanks again.
 

jafir

Well-known member
May 4, 2011
1,628
0
Northwest Arkansas
Yeah. On my 1999 there was another small relay there. On my 03 there is that metal jumper. The Idm is special circuitry inside the fuse box. Intelligent driver module or something like that. The drl features are enabled in the software of the BCU.
 

dragnet

Well-known member
Dec 23, 2008
120
0
Thanks jafir.

I'm wondering if my BCU might be toast then as the relay and jumper seem to be alright and all fuses are okay.

Wonder if the jumper in the top left corner is the resistor that the RAVE states connects the DRL relay, which sits above the turn signal relays, back to fuses 3 and 22 at a reduced voltage?