Whacky Daytime Running Lights System

[osudrewski]

98 Rolla, 138K miles, daytime system acting goofy. Three switch positions (off, 1 (which is parking lights, and 2 which is all lights) During nighttime, lights do not work unless a flashlight is positioned onto sensor by the windshield for entire duration of trip at night as if to "trick" the system into thinking its daytime. when switch is in position 0, lights on no interior. in position 1, lights on interior on. in position 2, lights off interior lights on. please help, i have no clue what else to do and im running outta batteries HAHA

[CraigW]

There is another member on here currently searching for the DRL relay for a 98 Corolla. You MAY need one as well.

[osudrewski]

The DRL mud is ok, i checked it in my other car (00 corolla) anyone have any other ideas? maybe the switch in the turn signal handle?

[briandugas]

I'm having the exact same problem as the original poster. Any resolutions yet? This has stumped me.

[Tercel GTS]

I bypassed a DRL system on a corolla a few months ago for a similar problem. The one I worked on had the relay beside the steering columb just to the right side of it, and slightly higher. All that was required to bypass was cutting 2 wires and butt connect them together. If needed I'll look this stuff back up.

[briandugas]

Well, I spent all day today working on it. I'm not saying it was a grounding problem, but if I bypassed the Daytime Running Light Relay assembly control module, I got it to work.
Here was my test:
I disconnected both harnesses from the back of the headlights. There are 3 wires that feed into that harness.
I then used one harness as my test. I turned the headlights on and checked voltage to the harness. One wire read 12V. I used the engine as my ground. I then put the high-beams on, and a different wire read 12V. Only one wire at a time was testing positive. I then used the 3rd wire of the harness to repeat my test, since it should be ground. (The 3rd wire of the harness was in fact color coded correctly, and that wire returned back to the Daytime Running Light Relay Assembly.) When I used the 3rd (ground) wire of the harness to repeat my test, I wasn't getting 12V. I was getting upper 10's, low 11's. This made me believe the ground wasn't good somewhere. How could I get 12V if I grounded to the engine block, but 10V if I grounded back through the harness? Who the hell knows. I checked all my grounds, and couldn't figure it out. Maybe my Daytime Running Light Relay assembly is struggling, but I just replaced it with a good one from a salvage yard.
To fix my problem, I just paralleled my ground from the harness to a new ground in the engine compartment. The lights no longer need to ground through the Daytime Running Light Relay Assembly. They function like they should. The only difference is during normal daylight operation, the headlights are at full blast (not high beam). There used to be a difference between daylight running strength and full strenght. Then, high beam was even brighter. So I guess there were 3 strengths. Well, now I got 2 strengths. So when it gets dark, the headlights don't really kick it up a notch, since they are already at full strength. But, at dark, the interior lights come on in the car, like the dash lights. My high beams function like normal, either I can pull the stick to flash, or push it to leave them on.
All in all, i'm satisfied. I was about ready to just put the lights on a toggle switch and say "screw it" everything. But I'm glad I got it working. I learned a lot about reading a wiring diagram in the process. I hope anyone who finds this post in the future can learn from my problems. I read somewhere that someone who had my problem had it fixed by a salvage yard technician and traced it to a ground problem. I guess that is essentially my problem, but I guess I'll never know where the exact cause of the problem lies.
Brian