Step 1 - Preparing the wiring harness & switch
Like mentioned above, I ordered a heavy duty H4 connector triggered harness along with the kit.
About the harness. This harness has -
- H4 trigger connector to power the coil - This is not usable as is. I cut the pins & used 2 out of the 3 wires. You can go for an H11 harness if you can find one.
- 2x H11 socket outputs for 2 ballasts
- 2x High beam solenoid power outputs
The wiring for the solenoid actuators isn't done too smart & is actually hooked up to the ballast powering wires. When using the harness as it is by tapping into stock high beam wire - if you flash high beam, it powers the solenoids as well as the HID bulbs for just a second. And frequently depending on use. Something we totally want to avoid for the health of the ballasts as well as the bulbs. So - I used the connectors from it for solenoids & the ground wire as it is. But I cut away the power wire from it, and hooked it up separately altogether with the stock high beam pin in the headlamp. This way - when I just flash high-beam, only the solenoid trips but fog light bulbs do NOT turn on unless their switch is ON already.
[[This tripped me off much later in the installation thanks to a negative switch control for headlamps in the car. If you are doing this in a similar Maruti - Please simply connect BOTH - the read & black wires from the solenoid directly into the 2 respective high beam & ground pins of the stock H4 connector. I learnt this after I had put everything back together & reinstalled the bumper. So instead of removing everything again - I used another small relay to work around this problem. More on that later!]]
This is how the harness looks after my modifications. H4 socket removed. positive wire of both side solenoid wires connected using an external red wire.
For a longer lasting & stronger connection, always use shrink tubes over solders & if possible reinforce the connection by adding a zip tag near it.
Preparing the fog light switch
The switch is for Celerio/Swift/Ertiga etc till recent generations. So it has power inputs for 12V, illumination, illumination brightness etc. I originally planned to take a 12V & ground wire from the engine bay ACC fuse to the switch. However, courtesy @
audioholic's Celeriofog light installation thread on this DIY forum, got the tip that I could simply route the wires from the headlamp leveling switch right besides. In the AltoK10, there is no backlight for the leveling switch. Just a 12V input, GND and output for the actuators up front. Simply prop out the leveling button using a screw driver & unhook the plug. Remove the pin using a needle from front. Push in the red and black wires into respective 2 pins in the socket & put the switch back in.
I couldn't find the coupler (G151) to connect to the back side of the OEM fog light switch. (I was lazy to search too much.) So I went a simple crude way & soldered wires to the back of the switch. It has total 5 pins on back. When looking at the pins from back of the switch with the notch on top, do the connections as below -
- Connect pins 1 & 4 together. Black wire.
Pin 1 is GND with the green indicator in series. This light will glow when switch is "ON". Pin 4 connects to the backlight illumination GND. Extend another wire from it, to connect to actual GND. - Connect pins 2 & 5 together. Red wire.
Pin 2 is for 12V input for the switch itself. Pin 5 is for the backlight 12V. Extend another wire from it, to connect to 12V supply. - Connect a red wire to pin 3
This is the 12V output from the switch, when turned ON. This is the wire that will actually trigger our relay harness. The wire we will push from engine bay, will get hooked up to it.
Connect a 3 slot connector at the end for these. The 12V from leveling switch will connect with the edge red wire. GND from leveling switch will connect with the black wire. And the wire that we'll insert from the engine bay (sourced from the relay harness H4 low beam wire) will connect in the middle red wire of this connector.
This is how the finished product should look like. I have also included a shrink tube for better wire management.
Use the existing firewall grommet's protrusions to make a tiny hole & insert the relay power wire into the cabin. Push it in till you see it lying down into the driver's foot-well.
After completing the connections, this is how the final assembly should look like. Push the switch into the slot carefully without getting any wires stuck in the sockets.
Here's a quick test. The backlight is ON & since the button is pushed in, the green light is also ON.
Our work inside the cabin is complete here! Now what remains is the installation of the projectors & completing the wiring.
NOTE - We wired this switch for power from the headlamp leveling switch. This switch gets power when the position lamps are turned on. i.e. headlamp stock is turned 1 click forward (or 2 clicks as well). This means the switch we added will function only when at least position lights are turned ON, which is perfect. This means we'll never have a situation where we are using the fog lights but have forgotten to turn on the tail lights while driving in the night.