Cakeboss107
Member
Ok so I just bought some led 7440 bulbs for my dtrl and installed them but they won't light up it tried to flip them and still no luck any ideas guys
Dtrl switch to led won't light up
- Thread starter Cakeboss107
- Start date
you probably have to spread out the metal contacts a little. otherwise connect to a 12v battery to test
- Location
- South Gate, CA
- Car
- 2003 FX45 AWD
He's correct.
Just make sure that your connection is dead on if not the LED might be bad.
Cakeboss107
Member
I tried them in the 7443 parking light light sockets and they work they just blink fast but I ordered them specifically for the dtrl
---------- Post added at 12:03 PM ---------- Previous post was at 12:00 PM ----------
Do u think I need to install resistors on the dtrl to get them to work
---------- Post added at 12:03 PM ---------- Previous post was at 12:00 PM ----------
Do u think I need to install resistors on the dtrl to get them to work
SCY7H3
Member
- Location
- Toronto, Ontario
- Car
- 2012 FX35S AWD
DTRLs are 7443 not 7440. Turn signals are 7440 because all they do is signal.
- 7443 bulbs have two filaments inside meaning two sets of pins (4 total)
- 7440 bulbs have one filament inside meaning one set of pins (2 total)
DTRLs in the 1st Gen FX have two functions:
- DTRLs
- Parking Lights
So what's happening is you have the bulbs plugged in to work as one or the other function but not both. With parking/headlights off, you have the DTRL pins being fed power, with the parking/headlights on, you have the other pins being fed power.
LED's are also polarity dependent, so depending how you turn your bulb around, you either get one of the functions above or the other, not both with a 7440 bulb. Try turning your headlights on and see if it lights up.
---------- Post added at 03:34 PM ---------- Previous post was at 03:30 PM ----------
Nope, LEDs have resistors built in, you only need special resistors for the turn signals to work but for DTRLs, there's no system that would prevent LEDs from not turning on.
On odd occasions the pins might be too thin preventing the socket from creating contact.
- 7443 bulbs have two filaments inside meaning two sets of pins (4 total)
- 7440 bulbs have one filament inside meaning one set of pins (2 total)
DTRLs in the 1st Gen FX have two functions:
- DTRLs
- Parking Lights
So what's happening is you have the bulbs plugged in to work as one or the other function but not both. With parking/headlights off, you have the DTRL pins being fed power, with the parking/headlights on, you have the other pins being fed power.
LED's are also polarity dependent, so depending how you turn your bulb around, you either get one of the functions above or the other, not both with a 7440 bulb. Try turning your headlights on and see if it lights up.
---------- Post added at 03:34 PM ---------- Previous post was at 03:30 PM ----------
Nope, LEDs have resistors built in, you only need special resistors for the turn signals to work but for DTRLs, there's no system that would prevent LEDs from not turning on.
On odd occasions the pins might be too thin preventing the socket from creating contact.
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Cakeboss107
Member
Thank a lot man good info really appreciated
SCY7H3
Member
- Location
- Toronto, Ontario
- Car
- 2012 FX35S AWD
You're welcome 
Sent from my SGH-I747
Sent from my SGH-I747