Rear Power Socket Electrical Question

[TCon]

Hi everyone,

Does anyone have a diagram for the wiring of the rear luggage compartment (F11) power socket. I thought I had one but I was wrong. I said id would ask here first before Google as that can give false information and have me running around in circles for hours. I'm planning on installing a train horn and when its done I'll post a good write up with picks, diagrams and links if anyone is interested. 

The intention is to power the air compressor from the power socket, assuming this is a switched power source.  Before I start pulling things apart I would like to have all the information at hand. Also if anyone has any insight to a better way to go about this or pervious experience in doing this would be grateful of your opinions. 

 

[Greydog]

Hi Tony

That's different !! a Train Horn !!

I thought the rear sockets were live until the car goes to sleep 

You could take a switched feed from the rear fuse box to control a relay as the main power source for your BEEE BAHHH horn God thats going to be loud

Dave

[TCon]

'God thats going to be loud' 

That's what I'm hoping 😉 although "train horn"  could be an exaggeration. The horn was advertised as such but might just be a loud air horn. But it does have its own built-in air reservoir and I am adding a 1ltr air tank and a 120psi compressor, a 70-100 psi pressure switch connected to a momentary switch. I have had enough of idiot drivers and fools strolling across the road who don't care to move out of the moving cars way. 

So I'm going to make them think twice next time. Oh and I have a dashcam too so funny reactions will be recorded. 😜

I kinda want it to be powered from a switchable power source so the compressor doesn't keep running all night if it sprang an air leak. That way it shouldn't burn itself out or drain my battery. 

 

 

[Greydog]

Morning 

Where are you going to mount the compressor up front under the bonnet or in the back? Where ever it is I think I would take a feed with an appropriate in-line fuse direct from the battery (in the boot or the jumpstart point under the bonnet) through a 30/40amp relay to the compressor. I would switch the relay from an ignition controlled source such as the radio in the boot or heater fans upfront.

I know what you mean about the "meandering masses" we keep the horses at a yard that is accessed by a 3/4 mile "Private" single track road. Since the first lock down and because it is paved the meanderers with there dogs and children have adopted it as they can wander up and down and not get their white trainers dirty !! Explaining that the road is "Private" and not a public right of way can earn you some serious abuse and often the men are as bad ??🤣 One group of mountain bikers have broken down a fence to access a local forest where they have dug jumps and rams. I have repaired the fence several times but they somehow think they have a right to do what they like one of the girls at the yard challenged them and was told **** Off we aren't doing any harm !! Maybe a minor heart attack when the Gatwick Express sneaks up on them would work and be damn funny to watch

Dave

 

[TCon]

Morning

The plan is to mount it at the rear under the boot. In the engine bay it was just too tight. On the rear underside of the F11 in the center is a plastic box which holds the cars air compressor for the rear air bags, but to the right of it is an empty plastic box which when removed has enough room for the compressor and the air tank. Its also right beside the grommet to the boot which will allow me access to power inside. The actual horns are going to be fit into the space between the rear bumper cover and the body of the car. Its very tight but with a little effort, its possible. Yesterday I took out the right rear boot covers/panels to gain access to the power socket. I have connected in a wire to the power socket and have it ready. I will add an inline fuse for both the compressor and the switch/solenoid power source. The power plug in the boot already has a fuse but I'll add an inline one anyway. I have added a diagram of what I'm thinking of in terms of wiring. Although your thoughts of using a relay sounds appealing.

[Greydog]

What current is the compressor drawing (the X5's suspension compressor has a 30a main fuse and a 7.5a control fuse) at 20 or 30a I would certainly look at putting a relay in line controlled by the switch 

Don't sound it without a warning to your passengers 😂 you could have a cardiac arrest on your hands 🤣

[TCon]

The compressor is only at max 10 amps so should be fine. If it was any higher I would probably put in a relay but its not a lot of current and it will only be running for a short time as it flows 0.88 cfm at 0 ps so it should fill both the 1 ltr tank and the reservoir to 100 psi in less than two mins from empty. After use it will kick in again when the pressure is below 70 psi. 

1 hour ago, Greydog said:

Don't sound it without a warning to your passengers 😂 you could have a cardiac arrest on your hands 🤣

Nappys are a must now for passengers 😂

[Greydog]

2 mins while it recharges    just enough time to jump out and drag the body with the startled expression into the bushes out of the way 😲   Brilliant we need video 

[TCon]

53 minutes ago, Greydog said:

2 mins while it recharges 

That's only if you completely discharge the two tanks 😉 I'll definitely do a right up with pics, diagrams and links if anyone want to use it as a guide....might even put some dashcam footage 🙄