Guys,

I have been searching for fog light mods to find part numbers and what not, it seem what what I found it tends to be a personal preference of what fuse it is switched from. 2010 I4 TSX.

What I am trying to do is install an OEM fog switch by the VSA switch just so I can have manual control to turn them off as needed. Then I want to trigger to be on as DRL but also keep using the fogs anytime the lights are on. I prefer the look of fogs as DRL over the factory DRL.

I see some guys just tap in the stock wire with a bypass that allows manual control plus factory control. I don't want to touch the factory harness so I purchased some H11 pigtails to use and wire this up completely separate.

As I thought through this I was going to use a piggyback on the DRL circuit and pull the primary fuse, but I believe that circuit is dead when the headlights are on. Then the headlight circuit will only be live with the lights on, getting me where I am right now. I want to maintain the lights staying off with remote start, otherwise I would wire to a switched source like headed seats and be done.

All that and the question - should I install two piggybacks on the DRL and fog fuse and use (1) diodes and connect to the same relay or (2) install two relays so the piggyback wires never are on the same circuit (since they will be controlling the coil), then just jumper the primary side of the relay. I am not sure what best electrical practice is. I have used diodes before but wonder about the two relay option (cost is irrelevant as I have both). I am using LED bulbs FWIW, low enough current draw for the primary circuit.

When I finish I will post up the parts list and part number. In my searches (and maybe I just completely missed it) I didn't find everything I needed within one thread. I basically have the harness made to the relay, waiting on wire loom to clean it up before I install it.

 

put your fogs onto an accord fog switch. you now have 100% control of them.

pull drl fuse and I am most positive you still have Hi beams.

you seem to want the drl to turn on the fogs and you control them too.
while noble there is a lot to go wrong. and if you F up it wont be a fuse but a MODULE that goes tits up.

just put them on the switch and leave the swith ON when you turn off the car/ when you start it up you have your drl/

just saying.

 

I wasn't worried about losing high beams. I also do not want the lights on when the car is warming up with remote start. This is where the DRL fuse piggyback helps.

I only want the switch if I need to kill the lights completely from the DRL circiut. Really not necessary but for $20 I might as well have that option.

I am not worried about messing any circuit up. I have dealt with more complex circuits than this, but since I am a mechanical guy I ran the idea by an electrical buddy. He confirmed my concerns about potential issues with diodes (although I haven't had issues in past circuits with a decent diode) and recommended 2 relays. Either way I listed will work, but I chose to go with separate relays to keep both signal sources completely independent.

Just waiting on the wire loom to come in and the switch so I can install. Finished the harness for the most part tonight. There really isn't much to it and I like the option of being able to go back 100% stock without any cut wires.

 

if you use your hand brake like ceb says you should then your drls will not be on with remote start.


of course you can use relays,,,,,the chinese make some good ones.

a module is not a circuit.

but you seem to know everything,,,,,you and your electrical buddy,,,,,

 

I didn't make this post to debate what I wanted to do with you. Your point about the emergency brake is valid and I appreciate that comment, I still want to keep it separate.

I know what a module is, I program them quite frequently on other vehicles and understand the different modules on today's cars. Again, using the logic of having signals on the coil poses no risk to the modules (which by the way are within the circuit). I posted this information so others searching (like I did) would see the proper information.

If you disagree that is fine, others searching can review the comments and use the information as they see fit. I was able to answer my question and provided the answers to what I believe to be the best option to suit my needs.

What I don't appreciate is coming to the forum to get questions answered to be challenged about what I want to do with smart remarks.

 

Using the hand brake won't work for this, the DRL fuse is hot when switched on. The fogs are also always hot.

What I ended up doing was removing the DRL fuse and tapping that location for one hot wire for the fogs like I planned. That works well as a switched source and stays hot as long as the ignition is on no matter the status of the DRL. The only downfall is the fogs are on with remote start. I am waiting on the Honda switch to come in to install that in this wire.

Since the fog fuse is always hot, I ended up changing the plan with the 2nd relay. I am using a SPDT along with a SPST relay. The double throw is controlling which signal I send to the single pole coil to turn the fog lights on. In the NC position I send the DRL signal, in the NO position I use the existing fog harness for the signal. I have this also driving the SPDT relay's coil. This prevents any circuit from crossing paths.

I purchased an H11 extension harness and used that so I could still keep my factory wiring. FYI, I am using LED fog lights so my current draw is around 0.5 amps (measured).

I will update with the proper Honda switch part number but here is what I purchased or used that I had around the house:

Heavy duty min fuse holder (with weatherproof cap) - used a 5a fuse
30' black 16 ga wire (smallest spool they had)
30' red 16 ga wire (smallest spool they had)
1/4" wire loom (used about 20')
3/8" wire loom (used about 4')
Black electrical tape
Zip ties
Heat shrink tubing (as needed depending on connector used)
Heat shrink butt splice for 16 ga (box of 10 is enough)
Heat shrink push on terminals 16 ga (box of 10 is enough)
16 ga ring terminals x4 (10mm ring I think)
Bussman add-a-fuse
Dorman H11 harness (84783) x2
SPST relay
SPDT relay
H11 extension cable
Honda OEM switch (will add P/N when I confirm the switch is correct)

I installed the relays under the hood just inside the passenger fender. There are locations that they mount nicely. I basically build the harness wrapped in wire loom outside of the car leaving the ends without terminals until I can cut the final length.

I used a metal hanger to snake the wire through the firewall and that saved a bit of time from trying to get my hand back there behind the dash. I used the passenger side grommet as recommended in other posts. I just wanted to post what I did for my particular needs so if anyone is searching it may be helpful.

The fog lights operate with the automatic lights as normal with the factory fog light switch/in any condition the factory ones operate and they operate any time the key is on through the 2nd switch that will be added by the VSA switch. Everything can be removed if needed and the only thing left is a small hole in the passenger wire grommet.

Only thing I would want to do different is find a weatherproof relay with plug that I could make a simple plug and play harness. I could not find any locally.

 

Got the switch in and it is a perfect match. I am going to order a harness so I can get the right connector off it too, both together are around $35. This also fit's my wife's 2014 RDX. I just need to find the pinout on it to see which wire goes where. I will post up that info once I have it.

08V31-SMA-0M035 : Switch 09-13 Honda Fit
08V31-TK6-10030 : Switch harness 09-13 Honda Fit (kind of a waste but I can't find the connector to use)

Did my wife's RDX and was able to get a relay harness for it. Other than the wire going to the driver fuse box the harness is all plug and play and fits nicely in the driver front wheel well closest the driver fog light. I changed the wiring so the ignition on triggers both relay coils. This just helps cut back on noise from the relays when the lights flash with lock/unlock (one relay click instead of two at the same time just makes it less noticeable). I intended to take a picture of the harness but since I had to cut most wires in place I didn't want to undo my work

 

Found this pinout online (hope this guy doesn't mind the link): https://i.imgur.com/yx7sogf.jpg

Looks like top to bottom (pink, blue, black, gray, red)

Pink - +12V in
Blue - +12V out (switched)
Black - ground for built in indicator light
Gray - illumination ground (tied to VSA)
Red - illumination power/signal in (tied to VSA)

I will probably skip the illumination so I don't have to tap into the factory harness. Looks like I can get the indicator light to work just fine though.

 

Nice OEM fog switch.