JDM (and USDM) driving/fog light wiring issue - read if you have them!
I thought I would post this as I think it is, in general, a safety issue.
In short, Honda ****ed up. Bad, in my opinion. I'm not sure how many of you have noticed, but Honda only uses one 18 AWG (or close metric equivalent) to provide power to the fogs from the inside wiring/relay. When I installed my first set back in 98 or so I thought this was odd, but "Honda knows best" so I just let it go. Given my electrical background I should have trusted my own knowledge rather than them.
Fast forward to a few weeks ago when I installed an HID H3C kit in my JDMs. After installing, they only worked intermittently. Before I got pissed about the reliability of lowest-bidder Chinese products, I decided to troubleshoot the wiring. With the fogs on, the relay and wire were noticeably WARM. This is not good. The bullet connector behind the kick panel area was HOT. Too hot to keep your fingers on. I also noticed the connector sleeve looked a little charred (should be clear).
After wiring things up under the bumper I realized that Honda really did use just one 18AWG wire from the kick panel area all the way to the furthest fog, then a wire is run from that fog to the other one. The ground is similar- one wire to one fog, then the other is daisy-chained off of it. Assuming there is about 10' of wiring one-way (I think it may be a little more), that means that with the OE 55W lamps there is around 9A of current in the circuit and 1.2V of drop end-to-end. That means around 11W of power is consumed just in the wiring (about 10% of the total load).
This is unacceptable in my mind. I went ahead and took apart the harness in front and the harness inside the cabin and ran an extra wire between the two. I went from the relay contact (soldered to the connector) to an extra bullet connector that I attached to one of the fogs. I also ran an extra ground wire from the other fog to the grounding point in front.
I was pretty pissed to find this but am glad I got it fixed. I ran a 16AWG wire this time, so it should handle the half load a little better than the OE one, though I didn't do anything with it. I should have completely rebuilt it but I was too lazy for that. At least that circuit is carrying half the load now.
My HIDs now fire up on the first attempt every time. I think the voltage drop was causing the ballast not to light reliably.
Given how hot the wiring and connector was inside the car, and that the sleeve over the connector was melting, I think this is a safety issue EVERYONE with JDM or USDM fogs should consider. While the wiring is a little different between the two, the one wire that Honda put in the car and uses to carry current from inside to the bumper is the same on ALL 5gs and is independent whether USDM/JDM fogs are used.
I have to reground my usdm interior foglights....any idea on how to reach that bolt right next to that foglight switchlight console or is there another spot.
I untaped the loom up front and the loom in the car. I ran it in those looms (easy) and just piggybacked it with the loom in the fender (I didn't untape that).
I already had the front bumper off, aside from that, I think it took me an hour. I've done a lot of this before, though. I took the time to run it through the existing grommet for the OE wiring in front of the driver's door, behind the fender liner (lots of untaping and retaping).
it seems that there isnt a problem with the stock wiring until you tried to power HID's through it. Id say anyone running higher current draw lights through any harness, it should be upgraded
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With a 10% power loss, I would say that it should make for a noticeable difference in brightness. Problem is you can't do a side-by-side comparison.
My concern is with wiring that is getting hot enough to harden and crack the insulator jacket over time and potentially crack the insulation around the connector. Not to mention the OE bullet connector in the kick panel had lost most of it's plating. It was definitely overheated and probably even taken past it's rated current.
It was hot enough to concern me and I'm not overly anal about these things. Honda clearly exceeded what was prudent as far as design parameters go (IMHO).
You're talking about that orange wire with the banana plugs right?
Yea that wire is thin as crap, I would've made another harness with the relay in the exterior, and just use that orange wire as a low voltage trigger for the relay, run the power straight from the battery with bigass wire.
It's obviously not the first wire honda decided to under-rate *cough* ignition recall *cough*, crapass stock speaker wires too =-(
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The Trapezoid of Death is back.
So, not knowing this were posted & i went ahead n try to P&P my HID into my JDM fogs & now blew bout 4 fuses then ran a relay into from ballast/factory hardness still No GOOD.
if i was to make my 2nd attemp. how should i go about it & still use the factoy jdm switch to light up my HID in my JDM fogs?
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Thanks! You just saved me a possible future headache!
I'm glad I did a search before jumping in over my head. I bought a JDM foglight setup off of e-bay and I just finished replacing all of the power and ground wires in the wiring harness before I put it in, as well as running a new fog lead from the front over the wheelwell etc. Anyway, I went with 14 guage for the power wires and 16 guage for the grounds. I basically recreated the entire harness though and threw out the wires they sent me which were 18 and 20 guage. It came with an HID conversion kit so once I saw your post I knew what I should do. Guess I should get out there and finish it up!
Quote:
Originally Posted by marcucci
I thought I would post this as I think it is, in general, a safety issue.
In short, Honda ****ed up. Bad, in my opinion. I'm not sure how many of you have noticed, but Honda only uses one 18 AWG (or close metric equivalent) to provide power to the fogs from the inside wiring/relay. When I installed my first set back in 98 or so I thought this was odd, but "Honda knows best" so I just let it go. Given my electrical background I should have trusted my own knowledge rather than them.
Fast forward to a few weeks ago when I installed an HID H3C kit in my JDMs. After installing, they only worked intermittently. Before I got pissed about the reliability of lowest-bidder Chinese products, I decided to troubleshoot the wiring. With the fogs on, the relay and wire were noticeably WARM. This is not good. The bullet connector behind the kick panel area was HOT. Too hot to keep your fingers on. I also noticed the connector sleeve looked a little charred (should be clear).
After wiring things up under the bumper I realized that Honda really did use just one 18AWG wire from the kick panel area all the way to the furthest fog, then a wire is run from that fog to the other one. The ground is similar- one wire to one fog, then the other is daisy-chained off of it. Assuming there is about 10' of wiring one-way (I think it may be a little more), that means that with the OE 55W lamps there is around 9A of current in the circuit and 1.2V of drop end-to-end. That means around 11W of power is consumed just in the wiring (about 10% of the total load).
This is unacceptable in my mind. I went ahead and took apart the harness in front and the harness inside the cabin and ran an extra wire between the two. I went from the relay contact (soldered to the connector) to an extra bullet connector that I attached to one of the fogs. I also ran an extra ground wire from the other fog to the grounding point in front.
I was pretty pissed to find this but am glad I got it fixed. I ran a 16AWG wire this time, so it should handle the half load a little better than the OE one, though I didn't do anything with it. I should have completely rebuilt it but I was too lazy for that. At least that circuit is carrying half the load now.
My HIDs now fire up on the first attempt every time. I think the voltage drop was causing the ballast not to light reliably.
Given how hot the wiring and connector was inside the car, and that the sleeve over the connector was melting, I think this is a safety issue EVERYONE with JDM or USDM fogs should consider. While the wiring is a little different between the two, the one wire that Honda put in the car and uses to carry current from inside to the bumper is the same on ALL 5gs and is independent whether USDM/JDM fogs are used.
Ok, so I'm way too far along to take any pictures, but no worries user Jimbo24 already did! He didn't upgrade to a larger guage wire, but you can at least see some pictures of all the wiring harnesses and stuff. Trust me it's pretty straight forward. The front wiring harness you just need to re-create and wrap with the wire loom that the factory one came with. Then you need to run a wire up under the wheel well and through the rubber grommet in the firewall behind the rear wheel. This will come out behind where the fuse box is under the dash board. Then I also replaced the power lead from the fuse to the relay, and then from the relay to the wire that you just ran through the fire wall. The plastic fuse holder and relay connection are pretty simple just gently push the female spade connector out the back with a small screw driver. Be careful not to mangle it. Then clip off the old wire, open up the end of it as much as you can and solder the new wire on, slide it back into the plastic connector and you're done.
The stock wiring harness is perfectly fine if you use standard halogen bulbs. The maximum amp. rating for 18gauge wire is about 15/16 amps.
If you want HIDs then DO NOT USE THE STOCK WIRING HARNESS. This is a dumb move and you only have yourself to blame. Save yourself the time and don't be cheap, by getting an HID wiring harness. Even if you make one it'll take less time than rewiring the harness and prerun.
The stock wiring harness is perfectly fine if you use standard halogen bulbs. The maximum amp. rating for 18gauge wire is about 15/16 amps.
If you want HIDs then DO NOT USE THE STOCK WIRING HARNESS. This is a dumb move and you only have yourself to blame. Save yourself the time and don't be cheap, by getting an HID wiring harness. Even if you make one it'll take less time than rewiring the harness and prerun.
Still nothing wrong with upgrading that ridiculously small stock wiring harness while you've got it out. It will only take a couple hours even for the least experienced. If you ever decide to put HIDs in later you will want to do this, better now than later when you'll have to tear it all out to do it.
I'm glad I did a search before jumping in over my head. I bought a JDM foglight setup off of e-bay and I just finished replacing all of the power and ground wires in the wiring harness before I put it in, as well as running a new fog lead from the front over the wheelwell etc. Anyway, I went with 14 guage for the power wires and 16 guage for the grounds. I basically recreated the entire harness though and threw out the wires they sent me which were 18 and 20 guage. It came with an HID conversion kit so once I saw your post I knew what I should do. Guess I should get out there and finish it up!
You may want to replace that 16 gauge ground wire with the same gauge as the power wires or lower. A rule of thumb is to always the use same or thicker wire than your power wires.
You may want to replace that 16 gauge ground wire with the same gauge as the power wires or lower. A rule of thumb is to always the use same or thicker wire than your power wires.
Since the ground wires only have to run about 2 feet from the lights to the frame at most, I didn't think they would need to be as big of a guage. The power wires run almost 15 feet from the fuse box to the relay through the firewall out to the bumper and finally to each of the lights. That's a lot more than the ground.
Plus the only thing open when I went out to get the wires was walmart and the only thing they had was 14 guage in red, and 16 in black, soooo that's what I chose, mostly because I wanted it to be obvious which wire was which and didn't want to get lost in the future trying to sort them out. I suppose that was lazy, but so far so good. The lights are working great, and no problems with the wiring harness getting hot or melting.
Still nothing wrong with upgrading that ridiculously small stock wiring harness while you've got it out. It will only take a couple hours even for the least experienced. If you ever decide to put HIDs in later you will want to do this, better now than later when you'll have to tear it all out to do it.
There is no need for that if you get a dedicated HID harness. I will be personally making my own and use 16/15 gauge for it. Plenty enough for the draw. As far as the prerun, it will only be used to magnetize the relay on the HID harness. This requires milliamps, and if at most, 1 amp.
My brother-in-law played around with a multimeter on his HID setup and measured the ballasts pulling 9amps of current during warm up and stabilizing at around 6amps. Like I said before, 18gauge is safe to use for up to 16amps at 600volts.
FYI, the harnesses for both headlights use the same gauge wire if not thicker by one gauge. So if you're going to be upgrading your fog harness you should also be worried about your headlights as they are probably on more frequently than fog lights.
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