Trying to understand electrics under middle front seat

[simonpelly]

Hi Folks,

Just picked up newly acquired Defender 110 CSW 300 Tdi 1997 vintage. In a happy place at the moment.

Creating a list of jobs/oddities and generally trying to get familiar with it.

Noticed under the front middle seat a bundle of electric wiring which do not understand.

Also, under the front middle seat there is a ECU unit which has me confused too. Why would this be present on this vintage of Defender?

Please see images attached.

Could folk help me get to grips with this.

Thanks,

Simon...

[Scotts90]

Well the ecu is (as it says on it) for your EGR valve...exhaust gas recycling valve fitted to later 300tdi engines for emission control.

As for the other wires...the black plug mounted to the front is the for the OBD (on board diagnostic), allows you to programme the 10AS alarm ecu etc. The other multiplugs I have no idea but I'm sure someone with a similar vehicle will be able to enlighten you! The one with the rubber cap could possibly be an auxiliary power feed for a centre cubby if fitted.

[simonpelly]

Thanks. Had misread the label and not internalised that this was for the EGR. Will take a closer look at the alarm system - not convinced any of the immboliser, etc... are working. Good thought on auxiliary power feed.

[Peaklander]

First thing about the alarm is that it also controls the interior lights. The door switches (x5) and the bonnet switch all go to the 10AS unit behind the dash above the driver's right knee. The interior lights are actually driven on/off by that box sensing that door has opened / closed. Therefore it does things like switches off the lights when then ignition is selected, or after 15 seconds following all door closes or something (can't quite remember!). If the alarm unit is working at all, then at least this function should be available.