Hi all,

I've finally got around to doing a permanent install of my sat nav after having it for 5 years. I've taken the feed off the rear wiper fuse which is switched live with the ignition as I didn't want it permanently live.

The kit came with a piggy back fuse but without a multi meter I couldn't work out it the top spade of the fuse socket was live or earth.

I've assumed the live is the top one so power flows down the fuse and out at the bottom but can you confirm this is correct.

The car is a mk3 2.0tdi 150 manual diesel scout.

Thanks all

20250710_164456.heic

Hopefully this will help show what I have done. Is the direction correct ie is positive at the top and earth at the bottom on the fuse holder blade .

Thanks

It really didn't make much difference.

I posted a couple of pics previously here https://www.briskoda.net/forums/topic/516544-dash-cam-fuse-orientation/#findComment-5787064

Thanks Langers , that's a great description of how to check. Remove the original fuse and see if the accessory still works 👍

Sorry for the underline but something went strange with the font.

Just for information the back washwiper fuse I piggybacked onto had a 20amp rating which was higher that I expected.

The Nexbase hardwire kit included two piggyback holders for use depending on the dimensions of the fuse you planned on tapping into (the octavia seemed to have both versions in use in the fuse box).

As for the load draw of the nexbase itself, the piggyback kit from nexbase already had a 2amp fuse inserted, so that is all they draw which is 10% of the rear wiper fuse. Im sure there won't be any issues but I'll check using @langers2k advice.

I might be more concerned about fuses blowing though if I had tapped into 5amp supply.

The camera works fine though although I've postponed my plans to wire up the rear camera that came in the kit as it seem a faff to remove the rear boot panels and have to feed the wire down the concertina pipe connecting the boot lid to the cars body.

Cheers

I somehow managed to reply to the linked topic - whoops.

In my Occy, I've used F48 - the lane change assist. It's just one to the right of the rear wiper. I don't have lane change in my car, so I simply put another 2A fuse in the piggyback slot, and then put it in. It's engine operated.

I like it as if it blows, I won't mess with anything pre existing in the car. It's also nice as the direction of the tap then doesn't matter (useful when there's a big relay connector right below it, so the tap only fits in one way anyway).

Here's a thread with a photo of my mirror housing, after 20 minutes with the Dremel - I'm a bit OCD and like everything being perfect https://www.briskoda.net/forums/topic/532849-2019-mk-3-octavia-glove-box/#comment-5951130

Happy to send you over a photo of how I did things nice and neatly in the fuse box - I need to open it up to change the cabin filter and check the fuse tap anyway. I also covered the entire dash cam cable in cloth tape - I didn't do it in my last car, and with the airbag in the a-pillar, I figured it might be nice to avoid any vibration/friction.

When I fitted my dashcam, I just picked an empty fuse socket that had an ignition switched supply. As it was unused, it only had one terminal, so I knew which way to fit the fuse tap.

I managed to to a neat run up behind the rain sensor housing , along the passenger side headlining and down inside the a pillar. It pulled the A pillar cover back enough so I could route it behind the airbag sleeve. Then into the side of the glovebox under the panel and into the fuses.

The glovebox retaining arm is always considered challeng3 but ive never had an issue with it.

As it turns out the way I had done the fues was correct with the camera still working with the original fuse unplugged so all don3 and dusted.

Later in the summer I might have a look at the cable run for the rear camera but for now it can wait 👍.

Edited 12 July, 202512 Jul by 3rdoctavia

This is the correct orientation You will find that on VAG cars the top of the fuse is the hot or in for power and so the tap should be inserted with the pigtail DOWN You only need a 5 amp fuse at the most and a 2amp if you can find one as the camera only pulls a bit over 1 amp

Edited 13 July, 202513 Jul by Exkiwi
Added info

1 hour ago, Exkiwi said:

This is the correct orientation You will find that on VAG cars the top of the fuse is the hot or in for power and so the tap should be inserted with the pigtail DOWN You only need a 5 amp fuse at the most and a 2amp if you can find one as the camera only pulls a bit over 1 amp

Ah, mine goes up - I’ll double check tomorrow. It’s been over a year and it won’t actually go the other way. That said, as it’s an empty slot, it doesn’t make any difference.

5 hours ago, 3rdoctavia said:

I managed to to a neat run up behind the rain sensor housing , along the passenger side headlining and down inside the a pillar. It pulled the A pillar cover back enough so I could route it behind the airbag sleeve. Then into the side of the glovebox under the panel and into the fuses.

The glovebox retaining arm is always considered challeng3 but ive never had an issue with it.

As it turns out the way I had done the fues was correct with the camera still working with the original fuse unplugged so all don3 and dusted.

Later in the summer I might have a look at the cable run for the rear camera but for now it can wait 👍.

Glove box is fiddly but it’s not difficult - removing the pillar trim, on the other hand, is one of the worst things I’ve ever done! That said - do be careful it’s properly done. I would personally take the trim off, use cloth tape and secure it properly to the existing loom.

It’s not a real issue for the airbag - it goes straight through the pillar trim so a USB cable isn’t going to stop it. The issue (IMO) is more that it’s not the thinnest cable in the world, and you don’t want the frayed end being whipped at you when the airbag deploys. Similar principle to the muppets that put phone mounts/hard stuff on the dash/steering wheel. There’s a reason all that stuff is thin or soft plastic!

5 hours ago, OccyVRS said:

Ah, mine goes up - I’ll double check tomorrow. It’s been over a year and it won’t actually go the other way. That said, as it’s an empty slot, it doesn’t make any difference.

If you put it in with pigtail UP and power is at the top you are running the power through the original fuse to get to the second. TO prove what i say hook it up and then pull the original one Bet the camera goes off. Dont ask how i know. Also here is a link to installing a dual camera in a golf with instructions on how to remove pillar trim. Basically applies to all VAG models as it did on my Tiguan.. Make sure you feed the wire BEHIND the airbag or you could wear it in an accident and pull the camera off screen into your face

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-dash-cam-install/

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-a-pillar-trim-removal/ To drop govebox just push sown on little tab and it will come down as per instructions

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-glovebox-headunit-removal/

Autoinstruct has quite a few good guides for different models Have a look through

Edited 13 July, 202513 Jul by Exkiwi

6 hours ago, Exkiwi said:

Yes - if you're piggybacking off of an existing fuse then 100% this matters. If it's 10A or over it's unlikely to make much difference, but you are indeed running the accessory (camera) and original component through the original fuse. In my case, as I said, it doesn't really matter, as I used a blank slot.

Anywhere there is an airbag, I put wiring along an existing loom. For the dash cam, I used cloth tape to affix the camera cable, firmly, to the existing loom.

If you put it in with pigtail UP and power is at the top you are running the power through the original fuse to get to the second. TO prove what i say hook it up and then pull the original one Bet the camera goes off. Dont ask how i know. Also here is a link to installing a dual camera in a golf with instructions on how to remove pillar trim. Basically applies to all VAG models as it did on my Tiguan.. Make sure you feed the wire BEHIND the airbag or you could wear it in an accident and pull the camera off screen into your face

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-dash-cam-install/

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-a-pillar-trim-removal/ To drop govebox just push sown on little tab and it will come down as per instructions

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-glovebox-headunit-removal/

Autoinstruct has quite a few good guides for different models Have a look through

11 hours ago, OccyVRS said:

Yes - if you're piggybacking off of an existing fuse then 100% this matters. If it's 10A or over it's unlikely to make much difference, but you are indeed running the accessory (camera) and original component through the original fuse. In my case, as I said, it doesn't really matter, as I used a blank slot.

Anywhere there is an airbag, I put wiring along an existing loom. For the dash cam, I used cloth tape to affix the camera cable, firmly, to the existing loom.

I f you run a addafuse to a empty slot and have it the wrong way you are running it back through the original fuse to get to the second fuse to the camera Proveable by removng F1 and camera will have no power

9 hours ago, Exkiwi said:

If you put it in with pigtail UP and power is at the top you are running the power through the original fuse to get to the second. TO prove what i say hook it up and then pull the original one Bet the camera goes off. Dont ask how i know. Also here is a link to installing a dual camera in a golf with instructions on how to remove pillar trim. Basically applies to all VAG models as it did on my Tiguan.. Make sure you feed the wire BEHIND the airbag or you could wear it in an accident and pull the camera off screen into your face

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-dash-cam-install/

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-a-pillar-trim-removal/ To drop govebox just push sown on little tab and it will come down as per instructions

https://www.autoinstruct.com.au/manufacturer/volkswagen/mk7-golf/mk7-golf-glovebox-headunit-removal/

Autoinstruct has quite a few good guides for different models Have a look through

I f you run a addafuse to a empty slot and have it the wrong way you are running it back through the original fuse to get to the second fuse to the camera Proveable by removng F1 and camera will have no power

Yes, but what's the issue with this? If I am using a empty slot, and insert a second 2A fuse into the piggy back, then the current is either going through just the 2A accessory fuse, or is going through the 2A accessory fuse and the 2A 'original' fuse - no harm no foul, unless I'm missing something.

I agree, if you're using a populated slot then that's not the best thing ever, as you're putting two things through the original fuse and the two aren't protected seperately. However in my case, with an empty slot, it doesn't make a difference, as there's only one circuit (which is protected)?

Edited 14 July, 202514 Jul by OccyVRS

2 hours ago, OccyVRS said:

Yes, but what's the issue with this? If I am using a empty slot, and insert a second 2A fuse into the piggy back, then the current is either going through just the 2A accessory fuse, or is going through the 2A accessory fuse and the 2A 'original' fuse - no harm no foul, unless I'm missing something.

Power comes into the top connector and out of the top connector of the piggyback WITHOUT going through the piggyback fuse. So by inserting the piggyback with the tail pointing up you do NOT have a fuse in circuit.

3 minutes ago, PetrolDave said:

Power comes into the top connector and out of the top connector of the piggyback WITHOUT going through the piggyback fuse. So by inserting the piggyback with the tail pointing up you do NOT have a fuse in circuit.

The tail is always fused...

The only difference between the orientations is whether it goes through one fuse or two:

12 hours ago, Exkiwi said:

If you put it in with pigtail UP and power is at the top you are running the power through the original fuse to get to the second.

I f you run a addafuse to a empty slot and have it the wrong way you are running it back through the original fuse to get to the second fuse to the camera

Agreed - however in most circumstances, having both loads through the original fuse will cause no issues.

1 minute ago, langers2k said:

The tail is always fused...

I stand corrected 🙃

29 minutes ago, langers2k said:

The tail is always fused...

The only difference between the orientations is whether it goes through one fuse or two:

Agreed - however in most circumstances, having both loads through the original fuse will cause no issues.

Yes, so in my case it doesn't matter which way the tail is going (up or down), as I have no original circuit to worry about fusing?

Am I correct in saying that if my piggy back was orientated correctly, then I wouldn't even need the 'original' fuse, but could just use the 2A dash cam fuse?

In my case, I believe it is incorrectly installed (goes down as I don't have the space), but as it's going through the 'original' 2A fuse I inserted (in addition to the dash cam fuse already installed) in the piggy back, there's no issue?

TLDR - I used an empty slot, the tail is pointing up, but both fuses in the piggy back are 2A rated. Whether it's going through one fuse or both, doesn't really matter?

2 hours ago, PetrolDave said:

Power comes into the top connector and out of the top connector of the piggyback WITHOUT going through the piggyback fuse. So by inserting the piggyback with the tail pointing up you do NOT have a fuse in circuit.

I thought the same but Langers post and diagram from a while ago was a revelation. I imagined the fuse hibe4 being a parallel circuit meaning it would just flow straigt from the positive pin and into the tail if now inserted correctly. I'm reality though this doubles up the number of fuses it would pass through.

Cheers

Yes it will work only if you have both fuses in but Why. Do it the right way and its easier . If it wont fit in a particular fuse use one that it will. In our case we use heated rear seats as dont need them when temp never gets low and we dont have family

To put things plainly the circuitry is this When oriented correctly the current flows in the top and to both the fuses as shown in my pictures. Therefore if put in an blank slot you only need the top fuse for the pigtail circuit. If put in upside down the current must run back through the original fuse to get to the dual wire and then to the second fuse to the pigtail.. In this way if you dont put the bottom fuse in you wont get power to the second one There are several spare slots in most cars so find one where you can orient it correctly.

16 minutes ago, Exkiwi said:

Yes it will work only if you have both fuses in but Why. Do it the right way and its easier . If it wont fit in a particular fuse use one that it will. In our case we use heated rear seats as dont need them when temp never gets low and we dont have family

To put things plainly the circuitry is this When oriented correctly the current flows in the top and to both the fuses as shown in my pictures. Therefore if put in an blank slot you only need the top fuse for the pigtail circuit. If put in upside down the current must run back through the original fuse to get to the dual wire and then to the second fuse to the pigtail.. In this way if you dont put the bottom fuse in you wont get power to the second one There are several spare slots in most cars so find one where you can orient it correctly.

A) It was an empty slot

B) I have a big relay connector just below the tap, so anything in the lower slots (F46/47/48) won't work. The rest of suitable positions either have no connection at all, or only connection for one blade. There are a couple, but they're like F12 or F27 - vehicle electrical system - too important to mess around with IMO.

13 hours ago, OccyVRS said:

A) It was an empty slot

B) I have a big relay connector just below the tap, so anything in the lower slots (F46/47/48) won't work. The rest of suitable positions either have no connection at all, or only connection for one blade. There are a couple, but they're like F12 or F27 - vehicle electrical system - too important to mess around with IMO.

If you're using an empty slot, it doesn't matter if there is only one connection.

That's what I did and it works fine as long as the tap is correctly orientated.

12 hours ago, daveo138 said:

If you're using an empty slot, it doesn't matter if there is only one connection.

That's what I did and it works fine as long as the tap is correctly orientated.

Did you not read where he said he has something BELOW it so can orient it correctly. I would be looking for another slot or a fuse that I could run it correctly but thats just me.

24 minutes ago, Exkiwi said:

Did you not read where he said he has something BELOW it so can orient it correctly. I would be looking for another slot or a fuse that I could run it correctly but thats just me.

Yeah, but as I said there is a lack of a suitable slots -

On 14/07/2025 at 22:49, OccyVRS said:

The rest of suitable positions either have no connection at all, or only connection for one blade. There are a couple, but they're like F12 or F27 - vehicle electrical system - too important to mess around with IMO.

My thinking (that seems correct) is that the direction of the fuse tap is entirely irrelevant if there is only one circuit going through it (in my case, the dash cam).

I could probably squeeze it tail down, but thinking about it from a basic electrical standpoint, I don't see what difference it will make - sure, the dash cam will then run through both 2A fuses, but that's pointless.

There is a difference in what is correct versus what works. Frankly, you could run it the wrong way off the wiper fuse and be absolutely fine. Worst case you somehow blow the 10A fuse, oh no, you've lost the rear wiper as well as the dash cam... I think I'd rather mess with that, than something important.