A pronounced rattling noise underneath the vehicle

Question edited for clarity, add maker.
Question moved to make model category.

Check the fuses and relays.

Fuse Box Diagram Suzuki Grand Vitara (JT; 2005-2015)

https://fuse-box.info > suzuki > suzuki-grand-vitara-jt-2...

In this article, you will find fuse box diagrams of Suzuki Grand Vitara 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 and 2015, get information ...

get it fixed.
take it to any mech,.
and id have him find the noise source and cause of leak.
then work from there.
we are blind and deaf there. we can do neither,

for leaks, we clean it prefectly then drive it 10 miles
and find true source
or use the UV dye test.

Hello and welcome to FixYa!

As a first course of action, I strongly suggest that you remove the positive battery connector and let it sit for at least 5mins. before reconnecting it. This will reset the system and can get your vehicle back to it's normal operation.

Hope this helps and thank you for using FixYa! Have a good one!

You obviously have to go back & check out the brakes
I don't mean take the vehicle back to the shop
I mean you getting involved

I won't be supprised you never got much done,regardless
of what you paid for.

Need to do all brake work yourself,if you want it done
correctly & safely

They use the same reservoir as for the brakes. mounted on the bulkhead under the bonnet

check front brake rotors sounds like there warped..or it might be in your drive shafts check for looseness

Obviously, in different markets, there will be different wiring set-ups. In Australia, both the brake lights and horn work when the ignition is off and they share a fuse. If your horn doesn't work, maybe your brake lights don't either.

You can do these things yourself a dealer will charge way to much

it could be because they are dirty. also the noise could be the back brakes. if its a squeaking noise it could be that they are dirty or that they are cheep brake pads and for the first couple of weeks they squeak. also when you got your breaks changed did the break shop cut the rotors because that cleans them up and makes the rotors like new.

Sounds like a wheel bearing. Get another diagnosis from a good shop or two..