DRL Daytime Running Lights 99 Astro LS

[tonka]

Bought my 99 Astro in August to replace my 87 Astro and noticed in the owner's manual that this vehicle is equipped with DRL. I never would have known this by driving the vehicle. Have never seen the DRL indicator light come on even when starting the vehicle. I also read that someone mentioned pushing the dome light override button 4 times and a chime for DRL. Pressing the dome override button has no effect and have never heard a chime aside from headlight and key reminders.

All of the rest of the lighting works fine except for the DRL. I have read some posts on here covering the topic. Some mention checking the parking brake switch, fuses, relays, overheated connectors, DRL diode etc.

Just starting into this. Have checked the fuses and they appear to be ok. Checked for overheated connector behind the parking brake pedal and it's good. My next step would be to check the parking brake switch. Is there more than one? My parking brake pedal assembly has a switch down near the bottom with a small gauge black wire connected. I assume for the indicator light on the dash. Light on the dash operates properly showing when the brake is engaged. There is an larger gauge (maybe 12 or 14 gauge) single orange wire with black connector draping over the top of the parking brake pedal assembly that is not plugged into anything. Wondering if there is supposed to be another switch located on this assembly that is missing.?

Trying to get the easy stuff out of the way and test before replacing parts. Any help is appreciated.

Tonka

[Phantom]

You can try locating the trouble by tracking the circuit with this wiring diagram for the 99 Astro

[tonka]

Thanks very much Phantom. Will try checking it out this upcoming weekend (if it's not too cold)

[WoodButcher]

You don't say what the problem is, are they not on? are you looking for an on / off switch?, are you expecting an indicator light? if they are not on have you checked to see that fuse#15 is installed? I read that I can disable mine by removing that fuse, haven't tried yet so I can't say that it works.
BTW, in my 97 I have no indicator light.

[kornphlake]

My 2000 doesn't have an indicator on the dash and the DRL worked intermittently then not at all. I traced the problem back to the diode, but it took some head scratching and some time with the schematic to figure it out. Troubleshooting is pretty easy though if you've got the brains to figure it out, there are 2 relays under the dash, just behind the OBDII connector, they're hidden in a plastic cover so you have to look a little bit to figure out where it is, but it's really easy to get to, one of the relays is the DRL relay. With the schematic you can pull the relay out of the socket and probe the various contacts in the socket using an indicator light and multimeter to figure out when and where power is applied. You'll have to turn on the lights manually and cover or illuminate the ambient light sensor manually to completely test the system, finally the DRLs should only come on with the parking brake released and the transmission in a gear other than park. All these functions run back to the relay, with a little thought you can figure out which piece is not working correctly and you'll know what to inspect further. This thread might be some help, at least the schematics are shown and I list the troubleshooting I did at the DRL relay on page 2: viewtopic.php?f=76&t=9056&p=94636#p94538

When the lights didn't come on in my van, the problem was the DRL diode, of 2 vans I picked parts from in the junk yard 1 had a bad diode.