Bad DRL Module?
Thread Starter
Joined: Nov 2003
Posts: 6,216
Likes: 236
From: Wichita KS / Rancho San Diego
Bad DRL Module? Issues: The left DRL intermittently goes dead, otherwise shines bright, and the blinker always works. Right side goes dim when the headlights or fogs are on and the right turn signal indicator comes on and stays constantly illuminated. Otherwise, it functions perfectly.
Backstory: I replaced the right side socket with one labeled for a 88-92 car as the store was out of the correct one and it appeared identical. That is when the right side issue started. I replaced it with the correct socket after several months, and the issue has persisted although it doesn't dim quite as much. The left side issue started soon after installing the incorrect piece. Sockets and bulbs on both are new.
Did I fry my module with the incorrect socket?
Backstory: I replaced the right side socket with one labeled for a 88-92 car as the store was out of the correct one and it appeared identical. That is when the right side issue started. I replaced it with the correct socket after several months, and the issue has persisted although it doesn't dim quite as much. The left side issue started soon after installing the incorrect piece. Sockets and bulbs on both are new.
Did I fry my module with the incorrect socket?
Joined: Nov 2003
Posts: 11,332
Likes: 347
From: Jacksonville, FL (originally from Toronto Canada)
No, you did not fry the DRL module. It is essentially a pir of relays which switch between DRL and turn signal as needed, so there's basically nothing you can do at the front lamps that will damage the module.
I'm not clear on exactly what is not working. The front lamps have two circuits - a bright DRL & turn signal circuit and a dim parking/running light circuit. The bulbs should be dimly lit when the headlights are on. They should be brightly lit when the ignition is on and the parking brake disengaged (DRLs) and brightly flashing with the turn signals.
Your description sounds like the left lamp is never dim and that is a problem... probably a miswired socket. It sounds like the right side never goes bright. That's probably a burned out bulb - the bright filament and the dim filament are separate and one can burn out without affecting the other. This would also be the cause of the dash indicator, as well as the rear lamps, going on solid and not flashing when using the right side turn signal... that's by design.
I'm not clear on exactly what is not working. The front lamps have two circuits - a bright DRL & turn signal circuit and a dim parking/running light circuit. The bulbs should be dimly lit when the headlights are on. They should be brightly lit when the ignition is on and the parking brake disengaged (DRLs) and brightly flashing with the turn signals.
Your description sounds like the left lamp is never dim and that is a problem... probably a miswired socket. It sounds like the right side never goes bright. That's probably a burned out bulb - the bright filament and the dim filament are separate and one can burn out without affecting the other. This would also be the cause of the dash indicator, as well as the rear lamps, going on solid and not flashing when using the right side turn signal... that's by design.
Thread Starter
Joined: Nov 2003
Posts: 6,216
Likes: 236
From: Wichita KS / Rancho San Diego
Let me try to clarify. I did some additional observation, so I have a better idea of what's going on. As I said in the original post, both bulbs and sockets are new.
In normal operation, with headlights and fogs off, both DRL's shine equally bright, except that sometimes the left DRL will stop working for a time with no apparent cause. Start the car the next day and drive off, and they're both working again until the next time the left shuts off. The right side is always on.
When the headllights or fogs are on, the right DRL dims and the right indicator comes on solidly. The indicator will blink, however, when I actuate the turn signal. The left DRL stays fully bright when the headlight or fogs are on, and the turn signal flashes even when the DRL is not illuminated.
I have a spare (used) DRL module, but I don't want to bother replacing it if that's not the cause of the problem.
In normal operation, with headlights and fogs off, both DRL's shine equally bright, except that sometimes the left DRL will stop working for a time with no apparent cause. Start the car the next day and drive off, and they're both working again until the next time the left shuts off. The right side is always on.
When the headllights or fogs are on, the right DRL dims and the right indicator comes on solidly. The indicator will blink, however, when I actuate the turn signal. The left DRL stays fully bright when the headlight or fogs are on, and the turn signal flashes even when the DRL is not illuminated.
I have a spare (used) DRL module, but I don't want to bother replacing it if that's not the cause of the problem.
