I am installing a tracker that has a remote kill switch feature. I need to tap into the fuel pumps positive feed.

I have located the fuel pump under the fuel tank inspection plate and have unplugged the socket that connects to the fuel pump. This socket has 4 wires going into it. I have used a multimeter on all 4 wires with the ignition off then on and only one wire gives a reading, it is a variation between 0.20-0.40v with ignition on. All other 3 wires display 0v with the ignition both off and on. This has left me very confused.

Does anyone know which wire is the positive feed for the fuel pump?

Does anyone have a wiring schematic or diagram for a 2014 Peugeot Boxer?

Has anyone had any experience with installing a tracker?

Maybe there is another way to tap into the fuel pump's power? Maybe at the fuel cut off switch under the glove compartment?

All opinions are useful thanks!

I do not know how you are taking the measurements but the attachment shows the functions of the 4 pin pump connector. Pair 1/2 is for the tank float level measurement and the pump positive on pin 4 with the common negative on pin 3.
Incidentally the inertia fuel cut off switch interrupts the Negative to the pump pin 3 if it has been operated.
I am not sure but think the Positive on Pin 4 is only present for a short time when ignition is switched On and shut off unless the engine is started.

Whilst googling I found this comment on the Fiat forum that may be relevant to your intended use. I do not know if what is said is correct as it is contradicted in a later post:
"There are 2 fuel pumps.
1) A low pressure electric one on the top of the tank which you access from the smaller of the 2 'manhole covers' in the cab floor.
2) A high pressure mechanical one on the engine.
Once the engine has been primed with fuel by the electric pump, it is no longer necessary in normal temperatures because the engine pump will suck the fuel right through from the tank - (so the old anti-theft idea of fitting a secret switch for the electric pump won't work) Its only when you have run out of fuel, change the filter etc so the system needs priming, or it gets very cold so the diesel is too thick for the engine pump on its own, that you need the electric pump"
https://www.fiatforum.com/ducato/427...fuel-pump.html

Attached Images

File Type: jpg

Fuel tank pump.jpg (139.6 KB, 23 views)

Fantastic reply thank you.

Is this fuel pump in the jpeg from a 2014 Peugeot Boxer? Also where did you find this manual?

Very interesting point about this fuel pump maybe not being useful for my immobilising purposes. I wonder if anyone else out there has had experience with a kill switch attached to the fuel pump on a 2014 Peugeot Boxer or similar?

rayc would you know if the inertia switch is the one displayed in this video?
If it is then perhaps I can tap into the feed before the switch?

The inertia switch is the same one as I referenced and is the same as a Ducato. As I said it interrupts the negative supply to the pump when tripped.

The manual is one of the cheap DVD ones on ebay. It is fairly useful for X250, pre X290 models. It requires a certain amount of practice and patience, as an example I have attached a circuit that you can print off from it, in this case the dipped headlight operation. Don't worry that it says 2007 - 2010 as not much changed on the vehicles until 2014

https://www.ebay.co.uk/itm/Fiat-Duca...72.m2749.l2649

Attached Files

File Type: pdf

dipped headlights.pdf (326.4 KB, 2 views)

Do we know if the inertia switch interrupts the supply of the pump in the fuel tank or the pump in the engine? If it is for the pump in the fuel tank then I guess it wouldn't make any different installing a kill switch at the inertia switch or the fuel tank pump.

Thanks for that I'll be sure to purchase!

I think I will tap into the positive of the fuel pump in the tank and see if it immobilises the vehicle when running. It may be the only way to know for sure if Peter James' advice in the other forum is valid to my situation.

To answer your question when the inertia switch operates the negative supply to the tank pump is disconnected.

I am no expert but am certain as the low pressure pump in the tank is electric whilst the high pressure pump at the engine is mechanical e.g it is driven by the timing belt on the Fiat Ducato 2.3.

https://www.autopartspro.co.uk/carpa...mp/fiat-ducato

The high pressure fuel pump is definitely mechanically driven.
I would have thought you will need to use the same source as the ignition switch uses to stop the engine, I've no idea how to do that though and as Ray has cautioned, there is a need for caution as all operations are routed via the various electronic control units.

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OK, so I am trying my best to follow (apologies).

Is the general consensus here that the low pressure pump (the one in the tank) would not immobilise the van if disconnected when mobile?
But even if it did, then simply tapping into the positive feed of that pump should be done with caution as it may not be a positive feed linked with the ignition switch?

Thanks for the advice guys.