[lemedico]

My 2021 Tiago AMT one morning gave me a massive sulk. I fired her up and after slotting into Drive, the wheel wouldn't turn as it did. It was ancient truck-like and impossible to even drive up to my mechanic's garage.

I have been an avid DIYer and I got around to fixing it immediately. One thing was for sure, there were no rat bites. I had already rummaged around the cabin and engine compartment to look for obvious signs of rodents.

There weren't any fault codes or warning lamps on my OBD2 scanner or instrument console respectively. This was very weird indeed.
A few youtube video searches gave me diagnoses ranging from oil leak, and sensor failure to steering rack replacement and whatnot.

A few months ago, I created a rear 12v power socket for this car.

https://www.team-bhp.com/forum/diy-d...er-socket.html (DIY Installation | 12v rear power socket)

I had then fuse tapped the EPAS {electronic power steering assist} fuse for the wiring. Just last night, I had used my tyre inflator to top up air and I suspected maybe that did some damage.

I opened up the cabin fuse compartment, whacked out the fuse tap and voila, there was a blown EPAS 5A fuse! I was very relieved to see the damage was minor and not youtube grade destructive.

There are spare fuses in the engine fuse compartment. I simply swapped it out and the job was done. Lesson learnt, not to use such high voltage accessories in the rear socket.

Have a look at this video I recorded for your better understanding of the task

https://youtu.be/p6iKPYRUygw

[lemedico]

There's a learning point here. Even fuse taps aren't foolproof against such mishaps. It is certainly much better than a jugaad wiring for your accessories. However, New wiring is best created from virgin fuses in your fuse box.
Sadly, there aren't any unused fuses in my car and I'm still thinking how do I mend this to prevent such a mishap happening in the future.

[Siddj38]

These fuse taps are actually directional. There is a certain orientation where they work as intended, i.e the additional fuse blows first if the added accessories are taking too much power.

Please do look into this.

[Reinhard]

This is a bit odd. If there was extra current drawn by the accessory socket - the fuse for the accessory should have blown in the tap (i.e. the one on top), not the EPAS fuse. I wonder why that happened. Was this the first time that you used that newly added socket? I wonder in case there was a short somewhere in the tap already.

Originally Posted by lemedico

Lesson learnt, not to use such high voltage accessories in the rear socket.

Also - if the accessories that you intend to connect to that socket are powerful enough to draw more than 5Amp - you should ideally use a different primary fuse socket, that supports 10 or 15 Amp on Ignition mode. Not a 5 Ampere fuse. Although this is more theoretical and chance of the wiring for the EPAS fuse circuit being different than the others are less - its a chance that car makers try to save every possible cent.

Its not the voltage - voltage for any car accessory will typically be 12V not more. Its the power and current draw that matters. Your accessory pulled more than 5 Amp current. (Still I don't see why it blew a fuse that is for something else).

I'd suggest keep an eye, and in fact keep a spare fuse added back in your car. If the EPAS fuse blows again - go straight to the ASC (after removing that fuse tap) - and get it checked. I think the EPAS-Immobilizer cabin fuse is shared. There might be an actual malfunction in those circuits that could have caused the blow-out, if not a short circuit earlier.

[Jeroen]

When you do a fuse tap try and find a circuit that is non critical and can’t interfere with normal driving.

Jeroen

[lemedico]

Originally Posted by Reinhard

This is a bit odd. If there was extra current drawn by the accessory socket - the fuse for the accessory should have blown in the tap (i.e. the one on top), not the EPAS fuse. I wonder why that happened. Was this the first time that you used that newly added socket? I wonder in case there was a short somewhere in the tap already.


I'd suggest keep an eye, and in fact keep a spare fuse added back in your car. If the EPAS fuse blows again - go straight to the ASC (after removing that fuse tap) - and get it checked. I think the EPAS-Immobilizer cabin fuse is shared. There might be an actual malfunction in those circuits that could have caused the blow-out, if not a short circuit earlier.

Originally Posted by Jeroen

When you do a fuse tap try and find a circuit that is non critical and can’t interfere with normal driving.

Jeroen

I have been using the new power outlet everyday ever since I had installed it. It was being exclusively used for my low powered ventilated seat cushion.

The socket itself seemed to be a bit wider than OEM, and my tyre inflator's plug was wobbling in it whenever I tugged on the wire shifting from one wheel to another. As a result, the pump would keep turning off and on again. That's what caused the electrical fault in the EPAS. I had kept the engine running whilst using the inflator.

Now this makes me question the safety of this particular fuse tap - It blew the wrong fuse! I am certain that I've put the fuses in proper orientation. Yet, it messed it up. I had to tap into the EPAS as there weren't any free fuses in the box to start with.

This was the first time I used the inflator in the rear socket. I don't know why did I do that. I've always used the front OEM one for it. Lesson learnt!

Do you recommend swapping the 15A fuse for a 5 or 7.5A fuse? Would it keep the systems safe? Or do I complain to the fuse tap vendor?

[Reinhard]

Originally Posted by lemedico

Do you recommend swapping the 15A fuse for a 5 or 7.5A fuse? Would it keep the systems safe? Or do I complain to the fuse tap vendor?

No, don't use a higher rated fuse, it undermines the purpose of the fuse, as it won't blow when the circuit actually draws more current than designed.

And the taps are all from our friendly neighbour. So there's noone that you can actually complain to, unless venting frustration out is the only purpose.

When you used the inflator, I assume your engine was running in neutral?

[lemedico]

Originally Posted by Reinhard

No, don't use a higher rated fuse, it undermines the purpose of the fuse, as it won't blow when the circuit actually draws more current than designed.

And the taps are all from our friendly neighbour. So there's noone that you can actually complain to, unless venting frustration out is the only purpose.

When you used the inflator, I assume your engine was running in neutral?

China, can't live with them, cannot live without them!

Until I figure out if I can live without a rear 12v socket or not, I am not disconnecting the fuse tap. Hopefully, the EPAS incident was a one-off. If something happens again, it goes in the bin for sure.

my Tiago is an AMT so yes, it was in neutral. Does that matter? I did not realise that the steering wheel has jammed up then itself because the car was already in its designated overnight parking space. I simply turned the engine off after doing the tyres.

[Reinhard]

Originally Posted by lemedico

my Tiago is an AMT so yes, it was in neutral. Does that matter? I did not realise that the steering wheel has jammed up then itself because the car was already in its designated overnight parking space. I simply turned the engine off after doing the tyres.

Ah sorry - I just meant to check that your engine was running, and the circuit didnt draw power from the battery when engine was off. Thats all. Didn't realize I was overcomplicating the query by adding gear position .

[Cresterk]

Why in the world would you tap a power steering fuse for these kind of jugaads? Atleast tap something like the AC fuse so even if it fails while driving, you would just be inconvenienced. Tapping critical things like EPS, ABS, ESC etc come with the risk of going under a truck in case of any errors while driving. Imagine if that fuse had blown in the middle of a hairpin while on a hill.

[Fastdriver]

Some tyre inflators are powerful @150 watt or 180 watt, drawing maximum 15 amp current. That's why I cancelled a Bergmann Typhoon digital tyre inflator @ Amazon just after ordering when I came to know that it was a 150 watt machine and my Baleno Alpha 2022 has 120 watt power socket. So if your tyre inflator is rated @ 180 watt or so you may use a less powerful one which will not blow the fuse. Also such gadgets/accessories (powerful or not) should be directly connected to the battery and should not share any other fuse (certainly not with the EPAS fuse). You can connect the power socket to the battery with a separate switch (or the ignition maybe) which should not be a big deal.

[lemedico]

Originally Posted by Fastdriver

Some tyre inflators are powerful @150 watt or 180 watt, drawing maximum 15 amp current. That's why I cancelled a Bergmann Typhoon digital tyre inflator @ Amazon just after ordering when I came to know that it was a 150 watt machine and my Baleno Alpha 2022 has 120 watt power socket. So if your tyre inflator is rated @ 180 watt or so you may use a less powerful one which will not blow the fuse. Also such gadgets/accessories (powerful or not) should be directly connected to the battery and should not share any other fuse (certainly not with the EPAS fuse). You can connect the power socket to the battery with a separate switch (or the ignition maybe) which should not be a big deal.

Lesson learnt. I'm not using the Bergmann anyway, it has started to smoke at plug . And I have an OEM inflator with the tiago, which I now use for all cars in the OEM 12v output.
The rear 12v output in my car is now exclusively used for the ventilated seat cushion of low voltage