I recently purchased the iJDM rear fog/brake light assemblies and was hoping someone had a wiring diagram to tap into the existing front fog lights. While the assembly does state to tap into running/brake lights the requirement here in the UK is that the fog lights must be operated separately with a tell-tale...hence wanting to wire them into the front fogs. Any help is much appreciated.
Rear Fog Lights
- Thread starter jibjab
- Start date
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- Plano, Texas, USA
It's difficult to find any info on rear fog light in the US as we simply don't have it here. Most people here such as Chris_Top_Her installed the rear fog lighg assembly but only hacked to the wires for tail lights and brake lights. You only need one fog light in UK on driver side (hence the passenger side for your LHD CX-5) and the easilest way is to find the wire going to front fogs near front dash fuse panel area coming out of US front fog light switch and tap it. But do you have to have separate front and rear fog light functions like from factory, or can you turn both on at the same time all the time? Otherwise an OEM headlight stalk switch with rear-fog switch position selling in the LHD countries is required.
I did read one person say they were going to wire rear fogs to the front fogs but all they noted was the use of a relay, not much of anything else. Correct, I just didn't like having an obvious single fog light with a toggle switch. Front fogs are not required/inspectable, only rear are required so most people get away with tapping the front fogs. Just didn't want to splice the front fog wires if there was another option such as a relay. I'm not good with car electricals and they have only gotten more advanced over the years so I'm always hesitant that something is going to blow up. lol.
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- Plano, Texas, USA
Not sure if there's a relay or not for front fogs in CX-5 but most likely it does. If you start to trace the front fog wire from switch output, with wireing diagram from a service manual, to a relay, then to the front fogs, see whether there's a connector available to disconnect and tap in the rear fog wire. I imagine your JDM rear fog kit is LED and I won't worry too much about the load issue on the relay and the wire itself. As long as there's a fuse, don't worry too much about screwing things up if you have some basic electrical knowledge.
There is a front relay for the fogs. Just looked at mine. Now, if I wanted to use a relay would this be the correct config:
30 Amp Relay
87 - Both fog lights
86 - Ground
85 - Fog light switch (front fogs)
30 - Power (would a 15 AMP fuse be sufficient?)
If so, what amp wire would be best? The lights themselves look to be around 5 so I was thinking of running 5 to the rear. The fuse holder is around 27. Would 27 for ground be good?
30 Amp Relay
87 - Both fog lights
86 - Ground
85 - Fog light switch (front fogs)
30 - Power (would a 15 AMP fuse be sufficient?)
If so, what amp wire would be best? The lights themselves look to be around 5 so I was thinking of running 5 to the rear. The fuse holder is around 27. Would 27 for ground be good?
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- Plano, Texas, USA
We use AWG gauges here and 5-amp automotive electrical wire you mentioned should be close to 14/16 GA wire and it's really depending on the length. Measure the approximate length from the proposed rear fog relay to the rear and do the calculation using the info found on the Internet. I'd try to use at least the same gauge/thickness/amp of automotive electrical wire come with the JDM rear fog light kits. My guess would be 10~12 gauge due to the long length for 2. If they're LEDs you may use 10 amp fuse but if they're incandescent bulbs you'd need a bigger fuse 15~20 amp. You can always try and see but for safety purpose I'd try to calculate the approximate amperage (for 2) and make a decision.
Does the JDM kits come with a relay? The general-purpose relay you described seems to be fine but you really need to check the specs of the relay you're going to get.
Ok, here is what I finally came up with and will be installing tomorrow.
30A Relay
87 - Fog lights
86 - Ground
85 - Mini blade fuze tap to 15A fog light fuze in EC fuze box
30 - Power
All wires will be 17A because the three stores I went to only had 5A, 17A, and 27A. There will also be a 15A inline fuze between the battery and relay.
30A Relay
87 - Fog lights
86 - Ground
85 - Mini blade fuze tap to 15A fog light fuze in EC fuze box
30 - Power
All wires will be 17A because the three stores I went to only had 5A, 17A, and 27A. There will also be a 15A inline fuze between the battery and relay.
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