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Solved: Motorcycle style Front & Rear Daytime Running lights - "Super DRL's"?

Joined
11 January 2021
Messages
693
Location
Ontario, Canada
Done: See post 8.

It seems everything on the road is getting bigger and we are getting harder to see. My search has turned up empty except a couple of threads on how many red/black wires you need to interrupt with switches to get the clock, dash, radio, and climate control to high intensity while still driving with your running lights on, which seems like a lot of wiring changes, not to mention the cig lighter, ashtray, and glove box lights.

(Here in Canada, motorcycles have to run with their headlights and tail lights on all the time; there is no switch. I notice them, so I do the same. This works fine because my other cars can adjust the dash and instruments to full brightness even with the running lights on during the day.)

What I would like to add is sort of a "super DRL", with the front DRL and rear running lights on with the ignition for greater visibility, without dimming the radio, climate control, clock, cc-set indicator, lighter, glovebox lights etc by turning on the running lights. Has anyone already performed this modification or know how to do it efficiently?

For the front, I plan to run @centerpunch mod from the fusebox to make white DRL's with switchback LED's in the front turn signal housings, that work as amber signals, but illuminate white as DRL's otherwise. For the back, it looks like I could repin F4 in connector C407 to ingition-on from the underdash fuse panel could do it, but that connector looks hard to access. F8 in C241 would be easier to access but finding ignition-on supply that could handle adding another few amps (brake/tails are LED) would be the challenge - perhaps run it all the way from the left fuse box? @drew is an expert in repinning connectors - done anything similar?


Thanks in advance for any insights.
 
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I’m out of town without my NSX or the electrical manual, but found this post.

 
Bingo! 1 wire around to F5 in C563.

However, this would mean the tail lights lights would not come on when the car is off and the "parking" light switch is on for parking visibility.
 
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Rear DRL done. The connector C535 (brown, 4-pin front left of trunk) has switched power, although it comes on at I (accessory) not just II (ignition), since it is for the (optional) cellular phone.
I repinned f5 in connector C563 (by right brake light lens) and ran a wire from one to one of the switched female 1/4" spades in C535. NB: The female wire color was red/black in the manual but red/white/grey in my car. Male wiring matched the red/black in the manual.
Similarly ran the other switched C535 spade to C557-f5 (by left brake light lens.) Again red/black in the manual but red/white/grey in the car. See pics.
PXL_20230921_224702681.jpg
This is connector C562 with f5 repinned (looking at R side brake lens):
PXL_20230921_224718662.jpg
Depin/repin f5 C557 (looking at L side brake lens):
PXL_20230921_224743419.jpg
Big thanks to @drew for a couple of spare female pins.

The LED 1157 & T10 bulbs draw 0.33 A for all 6, ~4 W. The original incandescent bulbs draw 4-5 A (50 W), which will drain the battery if you're sitting around playing the radio, if anyone still does that.
 
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Here is my issue: As expected, the running lights no longer come on with the switch when the ignition is off with the parking lights on. This means the rear running lights ALSO DON'T FLASH with keyless locking and unlocking if you had added either the Prime light-flash relay or @drew or @I_M_Legend keyless entry systems.

I'm contemplating Tee-ing the original running light wire that I de-pinned from the connector C563 back to my added-in running light wire with a Schottky diode so it can power the running lights but the diode will prevent the power from my supplementary ignition-on wire from activating the whole running light circuit. My question is: what else is on the circuit to C535? I know it's power for either a cell phone, but it doesn't even list as a connector in my connector list at the back of my electrical manual. Is anything else on this always-on wire in C535? Otherwise, why would Honda have a fuse in that circuit?
 
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Doh! I found the pic, but I missed the chart on 203-28. 🤔 That's the one I needed; I was looking at the other chart on 204-4 that omits C535 for some reason. I have the same manual (I also bought the 97-02 instead of the 97-01, but I haven't got around to taking out all the 2002-related pages yet. :))

So, the cigarette lighter is also on the ignition-on wire in C535. I definitely don't want the light circuit back-powering that, so I'll add a diode there as well.

Thanks!
 
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Completed. Here's how to do it to get tail lights when you're driving or when the parking lights are on, and also lights flashing during locking & unlocking. The 2 diodes are critically important:
  1. Depin red/white from C557 and C562 at the taillights.
  2. Repin both sockets with accessory wires and run back to C535 at the front left of the trunk.
  3. Wire a DIODE from brown/yellow in C535 to the union of those 2 wires. The rear tail lights will now come on with the ignition, so no need to have the running lights on, dimming the display, in order to have your tailights on for visibility.
  4. Connect the "old" red/white wire from 562 (or 557) to the new wiring, THROUGH A DIODE as shown in the diagram. The tail lights will now come on with the running lights when parked, and also flash with the remote keyless if you have that enabled.
  5. Insulate the old red/white pins from C557 & C 562. Double check diode polarity by testing if the lights come on with the ignition or the running lights. If one doesn't work, that diode is probably backwards.
The reason for the diodes is to prevent "backfilling" one circuit from the other. The diode at C562 prevents the ignition-on voltage from C535 from "back" powering the rest of the running light circuit, all the way back to Fuses 38 & 39. The diode at C535 stops the voltage from the running lights on Fuse 39 from "back" powering the accessory circuit, which includes the cigarette lighter. Without it, if the running lights were on without the ignition, the cigarette lighter could draw enough to combine with the rest of the running lights to blow Fuse 39. PM me if you want a diagram of it.

Diode added at C535:
PXL_20231112_215228913-EDIT (1)-min.jpg
Wiring diagram:
PXL_20231113_163032039-min.jpg

Side note: if you want the rear side running lights and the license plate lights as well, it's even easier. Run the same diode from C535, but then depin red/white from C534 right next to it. Run the wire from C535 and the original red/white to the old C535 location, BOTH THROUGH A DIODE. Be sure the diodes are pointing in the right direction.
 
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Very comprehensive solution! Check out this alternate approach by @dsmanion. Makes it possible to flip the switch to the parking light position (still have to do this manually, but avoids the battery drain issues) while not dimming the instrument cluster/radio/ccu, dependent on the dimmer setting.

 
Very comprehensive solution! Check out this alternate approach by @dsmanion. Makes it possible to flip the switch to the parking light position (still have to do this manually, but avoids the battery drain issues) while not dimming the instrument cluster/radio/ccu, dependent on the dimmer setting.

@dsmanion solution is a very elegant solution - Nice! I think I might prefer it. (Most recent Chrysler and Jeep vehicles are wired this way.) But didn't want to cut any OEM wiring. The solution here can be pulled out and repinned back to stock in about 5 minutes.

Note you'd still need to add decent DRL at the front to @dsmanion solution, which might be possible with very high power LED's in the front running lights. They would also have the problem of masking the front turn signals.
 
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