Foglight Bypass - Revisited
Posted: Sat May 16, 2020 2:08 pm
A long time ago, I had a 2005 Frontier, and had implemented the foglight bypass, where you could control your foglights independently from anything else. You could turn them on with no lights, low-beams, high beams, even when the the vehicle ignition was off.
When I ended up with this 2011 Pathfinder LE, I set about to do the same modification, but soon learned that there was no longer a removable relay controlling the foglight current. Beginning in 2009 (as far as I can tell), Nissan actually integrated the foglight relay into the circuit board on the IPDM, and hid it under cover, lock, and key, not allowing you access to it. I highly disagree with this move, due to the fact than a malfunctioning relay now means buying a whole new IPDM, for close to $300-$400...
On my Frontier, controlling the foglights independently of anything else was as simple as grounding out one pin on the relay, and thereby sending current to the lamps. Knowing this, I set out to investigate the traces on the IPDM PCB, and accomplish the same job.
Dissambling the IPDM, and searching for the correct lead:
After some (scary) fucking around, I determined the pin to ground on the PCB (marked with red paint).
I couldn't figure out how to safely disassemble the IPDM further than this, so decided I'd have to solder my lead onto the bottom of the PCB.
After that, I drilled a small hole in the IPDM top cover, fed my wire through, and sealed it with liquid electrical tape:
With the IPDM re-installed, I did a little testing to determine how I'd wire up my switch.
Now, I found a grommet near the steering column to send the wire through the firewall, buttoned everything up, and installed the switch in a blank spot right below the keyhole. All you have to do is ground the terminal, so with the switch closed, the wire fed into the cabin is simply grounded out on some bare steel behind the dash. Now, because this will turn the foglights on now with the engine not running and even no key present, I decided I should probably use 3-pole lighted switch, so I don't accidentally leave the foglights on and kill my battery.
Success! Now to do the H9 bulb mod and enjoy some nice clean, factory looking driving/fog lamps!
When I ended up with this 2011 Pathfinder LE, I set about to do the same modification, but soon learned that there was no longer a removable relay controlling the foglight current. Beginning in 2009 (as far as I can tell), Nissan actually integrated the foglight relay into the circuit board on the IPDM, and hid it under cover, lock, and key, not allowing you access to it. I highly disagree with this move, due to the fact than a malfunctioning relay now means buying a whole new IPDM, for close to $300-$400...
On my Frontier, controlling the foglights independently of anything else was as simple as grounding out one pin on the relay, and thereby sending current to the lamps. Knowing this, I set out to investigate the traces on the IPDM PCB, and accomplish the same job.
Dissambling the IPDM, and searching for the correct lead:
After some (scary) fucking around, I determined the pin to ground on the PCB (marked with red paint).
I couldn't figure out how to safely disassemble the IPDM further than this, so decided I'd have to solder my lead onto the bottom of the PCB.
After that, I drilled a small hole in the IPDM top cover, fed my wire through, and sealed it with liquid electrical tape:
With the IPDM re-installed, I did a little testing to determine how I'd wire up my switch.
Now, I found a grommet near the steering column to send the wire through the firewall, buttoned everything up, and installed the switch in a blank spot right below the keyhole. All you have to do is ground the terminal, so with the switch closed, the wire fed into the cabin is simply grounded out on some bare steel behind the dash. Now, because this will turn the foglights on now with the engine not running and even no key present, I decided I should probably use 3-pole lighted switch, so I don't accidentally leave the foglights on and kill my battery.
Success! Now to do the H9 bulb mod and enjoy some nice clean, factory looking driving/fog lamps!
