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Adding Cameras, Radars, Disco Balls, etc... (Fuse Locations)

14K views 48 replies 16 participants last post by  SSgtjrobertson 
#1 · (Edited)
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*01/07/2023 - Edit: added additional information to wire components in engine to the BJB (battery junction box) on post #28

You have the power! Well okay it's really the BMC but you helped. (If you don't get the reference then I feel sorry for your childhood)

Okay there seems to be a lot of confusion surrounding this topic. New and old members are constantly asking were to find either switched power (ignition) or constant power (battery hot) for one reason or another. Regardless the reason there is a correct and incorrect way of achieving this.

Most members do not feel comfortable splicing into physical wiring and truthfully I suggest avoiding it unless necessary (why add potential issues if it can be avoided). Scotchloks & T-taps are for scrubs (yes I'm talking to you!)

Fuse Taps are a good way to add additional components while leaving the factory wiring another. However there is a correct way to install these to prevent causing damage. If you're read this I'm going to assume that you have some method of reading voltage. It doesn't need to be an expensive DMM (digital multimeter) but something that shows you are working in the right direction.

So let's start with this example:
You want to install a dash camera because the general public is comprised of savages.

For this camera you need to have a constant source of 12 VDC power (battery hot) and a ignition source (a signal that indicates the vehicle is in use). Well unfortunately unless to are looking to run additional wires to the BJB (battery junction box) next to the battery a true ignition source isn't truly available at the BCM (body control module) but using a signal that is connected to the interior lighting circuit is the next best option.

The majority of Focus ST's in the USDM have an unused Fuse slot on the BCM that is connected to a constant battery hot so that will be you connecting point.

It is up to you to verify that the BCM Fuse slot has Fuse blade supports. Not all empty slots have them and if you attempt to press a fuse tap against the BCM's circuit board damage could occur

So let get things hooked up.
BCM (F61) = front and rear power points (hot whenever the vehicle is operating and off when exiting vehicle afte the engine is turned off)

BCM (F88) = Unused per ford. This is open to add additional components not exceeding 17 amps (85% of 20 amp maximum) *circuits exceeding 20 amps should be run directly to an open point on the HVJB (high voltage junction box) but that's a different post for a different time.
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Do not add fuse to lower slot in the fuse tap for F88. It will add power to components not use and could cause issues. Better safe than sorry.

Attention!
It's important to understand how a fuse tap works. Installing them incorrectly can lead to damage or negatively effect other components on the circuit you’re tying into.

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Correct orientation: The side the does not have the wire is to be placed on the source voltage (switched or constant). This allows the factory circuit to be left alone (Fuse 1) and allows for an additional component to be added on the circuit (Fuse 2)via the attached wire.

It is up to you to verify which side is source voltage and which is the load side (component) by removing the fuse and checking each side of the fuse holder. You have been warned for the last time.

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If the fuse tap is incorrectly installed all the load is carried by (Fuse 1) as it becomes the source voltage for everything.

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Wanna see what 9.5 amps on a 10 amp fuse looks like? Sure it worked for awhile but after a month this persons vehicle still smells like burning plastic. They were lucky as I've seen several vehicle fires in my career. One being fatal. Take the time to do it correctly!

So the above should get you what you need. All that's left is a good ground point which can be easily located at a factory location behind the panel on the passengers side footwell next to the BCM.

Hopefully this helps and if you have any questions I'm always here to help whenever I can.

Stay Safe
J
 
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#2 · (Edited)
Talk about the creepiest of perfect timing in this post.

For the first time, I'm enjoying the joy of fuse taps. I've always cut into and soldered wires (a scary thought but it's what we all used to do, or so I think).

That said, I couldn't figure out these fuse taps. Something so simple and I couldn't understand why there were TWO slots on them. ... it's because the fuse you're using (if using it) goes there. Legit didn't know that and I've been doing car audio and electronics for way too long to admit.

Thanks, man. Now to ensure I'm not melting anything.
 
#4 ·
Talk about the creepiest of perfect timing in this post.

For the first time, I'm enjoying the joy of fuse taps. I've always cut into and soldered wires (a scary thought but it's what we all used to do, or so I think).

That said, I couldn't figure out these fuse taps. Something so simple and I couldn't understand why there were TWO slots on them. ... it's because the fuse you're using (if using it) goes there. Legit didn't know that and I've been doing car audio and electronics for way too long to admit.

Thanks, man. Now to ensure I'm not melting anything.

If you don't mind my asking: How do you go about ensuring you're plugged in to the proper side?
Remove the fuse your planing on using.
DMM set to volts. Black lead to chassis ground. Only one side of the fuse slot will have 12VDC. The other will (should) show you either nothing or ground as it is the load.

So just remember that the fuse tap plugs in with the wire away from the source voltage.
 
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#3 ·
Duh ... figured it out with the DMM.
 
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#5 ·
I just replied when you figured it out 😆
 
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#6 ·
@itssocoldinthe I also use these when space is limited but will require another fuse holder to protect the addition component.
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#7 ·
Something similar to the above is necessary when attempting to utilize F61, as the typical Add-a-Fuse is too bulky to seat correctly. I tried a few different configurations, but the harness connector and/or the fuse panel frame makes this a tight spot. Because of this, I ended up using F85 for the switched power source.

SSgt- thank you SO much for all of your assistance with this and other novice questions.
 
#8 ·
Oh snap. I've been trying to use the fuse box in the hatch but haven't had much luck. I have voltage back there but couldn't get it out if any of my fuse holders.

I figured it was due to the add a circuit not working ... now I have confirmation. Much appreciated, gentlemen.
 
#10 ·
#11 ·
Oh snap! I'm not the only one who didn't know. That's a relief. :D
 
#12 ·
Remember that you still need to add a fuse to that wire. It's coming off the source voltage side.
 
#13 ·
Just found this post redirect from Focus Fanatics! OMG! I've been putting off the hardwire kit for my dash cam for six months because I couldn't figure this out. I had hardwired my wife's Hyundai Accent and she ended up with no brake lights and no ABS until I just plugged it into the cigarette lighter 😅

I'll be doing this over the weekend. Do you happen to know which fuses to tap into for a 2013 Hyundai Accent too :unsure:

Is the 22 Ranger similar? I'll need to get a dashcam installed on that guy soon too.
 
#14 ·
Just found this post redirect from Focus Fanatics! OMG! I've been putting off the hardwire kit for my dash cam for six months because I couldn't figure this out. I had hardwired my wife's Hyundai Accent and she ended up with no brake lights and no ABS until I just plugged it into the cigarette lighter 😅

I'll be doing this over the weekend. Do you happen to know which fuses to tap into for a 2013 Hyundai Accent too :unsure:

Is the 22 Ranger similar? I'll need to get a dashcam installed on that guy soon too.
LMAO on focus fanatics? 🤣

I'm sure I could help you figure it ...
 
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#16 ·
Trying clearing you cache.
I can seem them still.
 
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#17 ·
I recently installed underglow (I know) and used F88 as per this post. However, when I didn’t install a fuse in the lower section of the fuse tap, I lost all power to my dash. Looked in my owners manual and F88 is listed as the supply to a bunch of other fuses, not sure if your ST is different than my 14’ ssgt, but for some ST’s F88 doesn’t come unused!
 
#18 ·
The entire point of a fuse tap is to use the source voltage with interfering with the original circuit.
 
#19 ·
G'Day Folks,

I have a 2014 Australian Delivered ST and I just want to confirm if the following fuses will be OK from the passenger compartment for powering a Dashcam. Current draw is 2A from battery and 0.5A from switched source.
  • Switched Fuse - F86 - listed in manual as 'Restraint System'
  • Constant 12v Fuse - F73 - listed in manual as 'Battery back-up sounder (alarm system), onboard diagnostics system

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I don't have a Sunroof fitted to my vehicle nor an alarm system from factory fitted.

Best Regards,
Jacko
 
#20 ·
What are you trying to add? How many amps does it require and does it require a constant power & ignition source?

J
 
#23 ·
Hey SSgt,
I’ve been trying to figure out how and where to connect my fuse tap on my car for one of those lit logos. All they’ve provided in the instructions is as seen in the photo. My buddy and I tried connecting it to the F30 slot but we got nothing from it. It seemed like it was because the fuse tap that I got wasn’t tall enough to allow the blades to go all the way in to the fuse box (I got the fuse tap that you can get at O’Reillys and seems like it looks exactly the same kind auto zone as well) so I wanted to get your opinion on it-slash-recruit your help.

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Thanks,
Bel
 
#24 ·
Can you show me what you're trying to hook up? When you expect it to turn on and more importantly turn off LOL
 
#28 ·
Even more power

So a member here asked an excellent question just recently. They wanted to add exterior accessories but have them triggered with the vehicle on (Start / Running). I haven't really touched on this before except when asked for help in a DM about hooking up specific items (WMI, Aux fuel controls, etc..).

Well I think I have a solution that will help with just about 90% of ST owners between 2013 - 2018. Also in doing this you will help to prevent future issues from corrosion interfering with you charging system if you have deleted the AGS (active grill shutters). Individuals like myself that cut out the actuator motor and plug it back into the AGS connector don't deal with this issue (or the associated DTC from the AGS module not communicating) but this doesn't mean that you cannot use the information I'm suggesting.

Honestly I feel pretty stupid just bringing this up now.

So of you're adding items that to the engine bay or exterior of the vehicle that aren't constantly on then this should definitely do the trick. I'll break this down into a few different configurations to help you decide which you want to use.


2013 - 2014 model years the AGS is powered by F35 (5 amp)

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2015-2018 model years the AGS is powered by F36 (5 amp)

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This circuit is hot both in Start & Run positions (any time the vehicle is in operation). Both feed a Yellow-Orange that runs from the BJB to Pin 3 on the AGS connector C1651.

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*note this is the problem connector that left unplugged becomes filled with moisture or corrosion and can effect the PCM's ability to control the alternator. Pin 2 Blue-Brown is the LIN BUS wire. Cutting and capping this wire will prevent accidentally shorting it to either power or ground and screwing anything up.

Option 1:

Fuse Taps in the BJB (battery junction box) located in the engine bay near the air filter box (which better be sealed!!! LMAO!)

You can fit a fuse tap into this space and it will provide a good trigger source for low draw items such as lighted emblems or other similar products. *Try and keep it under 7 amps.

Option 2:
You can use the same fuse tap to provide a low amp trigger source to fire a relay inorder to switch higher amperage loads such as lights or combinations of items that would exceed 7 amps in draw. (Lights, WMI, AUX fuel control, your 20th anniversary Fast & Furious LEDs) knock yourself out!


Option 3:
You can skip the fuse tap all together and cut the connector (C1651) out. Cap the LIN BUS connector wire (Blue-Brown). Use the AGS power (Yellow-Orange) and ground (Violet-Orange) to run the accessory or better the relay directly. *Remember this circuit has a 5 amp maximum rating. So use a relay if you're trying to hook up more than 5 amps.


Relay connection diagram:
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You can run a 10 gauge wire from the HVJB (high voltage junction box) unused fuse locations and then to input pin 30 on a relay. 10 gauge wire will comfortably handle 40 amps. Most 12 VDC automotive relays are 30 to 40 amps depending on what you buy.
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Match the midi bolt on fuse to the relay size. But it's OK to run a 30 amps fuse on a 40 amp rated relay just not the other way around (40 amp fuse & 30 amp relay)

Try to keep the relay mounted away from direct exposure of water or road debris. They do make "heavy duty sealed" relay packs but trust me they aren't.

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Also before I forget I always use automotive GXL wire. It's designed to hold up to the environment and is required by most automotive manufacturers for repairs.

As always if you have any questions just ask.

Stay Safe
J


@Belisarius
 
#29 ·
Even more power

So a member here asked an excellent question just recently. They wanted to add exterior accessories but have them triggered with the vehicle on (Start / Running). I haven't really touched on this before except when asked for help in a DM about hooking up specific items (WMI, Aux fuel controls, etc..).

Well I think I have a solution that will help with just about 90% of ST owners between 2013 - 2018. Also in doing this you will help to prevent future issues from corrosion interfering with you charging system if you have deleted the AGS (active grill shutters). Individuals like myself that cut out the actuator motor and plug it back into the AGS connector don't deal with this issue (or the associated DTC from the AGS module not communicating) but this doesn't mean that you cannot use the information I'm suggesting.

Honestly I feel pretty stupid just bringing this up now.

So of you're adding items that to the engine bay or exterior of the vehicle that aren't constantly on then this should definitely do the trick. I'll break this down into a few different configurations to help you decide which you want to use.


2013 - 2014 model years the AGS is powered by F35 (5 amp)

View attachment 413091 View attachment 413092

2015-2018 model years the AGS is powered by F36 (5 amp)

View attachment 413094
View attachment 413095
This circuit is hot both in Start & Run positions (any time the vehicle is in operation). Both feed a Yellow-Orange that runs from the BJB to Pin 3 on the AGS connector C1651.

View attachment 413099

*note this is the problem connector that left unplugged becomes filled with moisture or corrosion and can effect the PCM's ability to control the alternator. Pin 2 Blue-Brown is the LIN BUS wire. Cutting and capping this wire will prevent accidentally shorting it to either power or ground and screwing anything up.

Option 1:

Fuse Taps in the BJB (battery junction box) located in the engine bay near the air filter box (which better be sealed!!! LMAO!)

You can fit a fuse tap into this space and it will provide a good trigger source for low draw items such as lighted emblems or other similar products. *Try and keep it under 7 amps.

Option 2:
You can use the same fuse tap to provide a low amp trigger source to fire a relay inorder to switch higher amperage loads such as lights or combinations of items that would exceed 7 amps in draw. (Lights, WMI, AUX fuel control, your 20th anniversary Fast & Furious LEDs) knock yourself out!


Option 3:
You can skip the fuse tap all together and cut the connector (C1651) out. Cap the LIN BUS connector wire (Blue-Brown). Use the AGS power (Yellow-Orange) and ground (Violet-Orange) to run the accessory or better the relay directly. *Remember this circuit has a 5 amp maximum rating. So use a relay if you're trying to hook up more than 5 amps.


Relay connection diagram:
View attachment 413100

You can run a 10 gauge wire from the HVJB (high voltage junction box) unused fuse locations and then to input pin 30 on a relay. 10 gauge wire will comfortably handle 40 amps. Most 12 VDC automotive relays are 30 to 40 amps depending on what you buy.
View attachment 413103
Match the midi bolt on fuse to the relay size. But it's OK to run a 30 amps fuse on a 40 amp rated relay just not the other way around (40 amp fuse & 30 amp relay)

Try to keep the relay mounted away from direct exposure of water or road debris. They do make "heavy duty sealed" relay packs but trust me they aren't.

View attachment 413101
Also before I forget I always use automotive GXL wire. It's designed to hold up to the environment and is required by most automotive manufacturers for repairs.

As always if you have any questions just ask.

Stay Safe
J


@Belisarius
Alright so to just dumb it down cause this is a lot of jargin that I am unfamiliar with. You recommend putting it into the f36 slot for the fuse tap as it’s a five amp spot and it’s pretty much unused after you remove the AGS so this prevents any further possible problems in the event moisture gets inside the fuse slot or what not. Does the f30 slot work as well?
 
#35 ·
Hi,
I'm going to hardwire dashcam, and I have two questions. Can you recommend any other fuse than F61, since it's quite hard to tap and I can't find those prewired fuses in Europe (or aliexpress). Also, I measured F88 fuse slot and it has 12V on both blades - does it mean that I can tap it in any orientation?
 
#36 ·
I'm planning on adding a trailer wiring adapter and want to be lazy and connect the hot to an ignition switched circuit in the back, rather than running wire to the front.
Any suggestions for a 2016?

This adapter I got off etrailer specs output of 4.2+7.5=11.7A, but not input.
TEKONSHA | 118674 | T-One® T-Connector Harness, 4-Way Flat, w/Circuit Protected ModuLite® HD Module, Compatible with Ford Focus

I did try searching a bit and found some diagrams in this post, but am not sure what year they're for?!
The Engineer's ST
The 25A driver seat seems hot at all times.
The 15A rear wiper might barely be sufficient. Maybe it or another could trigger a relay running off the 25A circuit?

The rear fuse box is close to the cover, so I've got to find a compact 90 tap, or maybe get inside it and do some soldering for connections. 🤔

I added a lower rated circuit breaker in addition to a fuse on one of my previous cars to help prevent blowing fuses, as random U-Haul or older trailers are notorious for shorts. Might do the same thing again.
 
#37 ·
I'm planning on adding a trailer wiring adapter and want to be lazy and connect the hot to an ignition switched circuit in the back, rather than running wire to the front.
Any suggestions for a 2016?

This adapter I got off etrailer specs output of 4.2+7.5=11.7A, but not input.
TEKONSHA | 118674 | T-One® T-Connector Harness, 4-Way Flat, w/Circuit Protected ModuLite® HD Module, Compatible with Ford Focus

I did try searching a bit and found some diagrams in this post, but am not sure what year they're for?!
The Engineer's ST
The 25A driver seat seems hot at all times.
The 15A rear wiper might barely be sufficient. Maybe it or another could trigger a relay running off the 25A circuit?

The rear fuse box is close to the cover, so I've got to find a compact 90 tap, or maybe get inside it and do some soldering for connections. 🤔

I added a lower rated circuit breaker in addition to a fuse on one of my previous cars to help prevent blowing fuses, as random U-Haul or older trailers are notorious for shorts. Might do the same thing again.
So I just looked at what you're thinking about buying for the connections and here's my questions.

I see P&P (plug & play) style harness and a separate fuse loop. I'd assume that manufacturers would supply directions as to where and how to supply the converter box to be powered.

However, that being said, there's some rules when sizing a circuit. Ford requires per their documentation that a circuit be fuse to 135% its maximum draw.

So a 9 amp maximum draw @ 135% should be sitting behind a 12.15 (12 amp) fuse. That fuse should not be at a distance greater than 12" from any power source.

Even if you tie into another fused source wire, such as the main power to the RJB (rear junction box) anything before the smaller fuse is considered a potential danger.

Fuses protect wires, not things.

Likely the converter box will have a very small load requirement. The output specs are just telling you what it can handle so you can decide what sort of lighting and how many you can have on the trailer.

This being a trailer being pulled by a Focus I doubt you'll run into any problems.

But unless you can find an installation PDF online you'll probably just need to but it and see.

Either way shoot me a DM and I'll help you out any way I can.

J
 
#39 ·
I was looking for pictures of the rear fuse box itself, and in addition to eBay parts photos came across this post doing exactly what I am! 😳😁

This is for a 2013, so later cars like my 2016 Mk3.5 may be slightly different.

MK3 rear fuse box pins

Note it says you can trim the box to use a fuse tap.



One side is hot always, while the other is switched on with the relay.

 
#40 ·
So I got some more pics of the rear fuse box.
One side is switched, the mostly empty side which is the OPPOSITE side of the relay.

I wanted to use a 90 degree tap since I was only adding the trailer light wiring.
I wanted to minimize the chance of damage and haven't gotten one of the other straight style with the wire coming straight out of one leg.
This required removing the 1 screw holding the fuse box in and freehand routing off extra plastic with a Dremel.

Enjoy, hope this helps someone!
 

Attachments

#42 ·
I'm currently trying to source a switched 12v power for a Fuel-It blue tooth ethanol sensor gauge. I need to tap for the BT sensor itself but will eventually be tapping for the gauge as well.
I've seen the active grill shutter and the sound symposer connectors referenced for switched power sources...but am curious if a simple add-a-fuse will work equally for like F34/F35 fuses. Utilizing the connectors without cutting, i believe I would need to find a female connector end and wire up to the pins to be able to connect it like factory (amazon or radio shack type place I'd imagine would have the pins I could run the sensor wires to. The symposer connector isn't really a good option unless i hack it up..its kind of part of a big assembly attached to the symposer itself.
 
#46 ·
Sorry, ACS was never made available in the US Domestic Market Focus.

 
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