90 300tdi electrical problem

morning everyone and hope somebody may be able to help!! A problem has appeared and I’m struggling to find an answer.

First arose when I turned the ignition off, assumed it was a faulty ignition switch or fuel cutoff solenoid. Replaced both and fine for a few days but now problems back.

If I pull Fuse 2 in the passenger compartment fuse box, ignition will cut out when turned off. However with fuse out - if I flash headlights or horn the radio and interior light turn off.

I understand that the interior light is connected via the engine bay fuse box to pax fuse box 2, I’ve had condensation in cab - could that be causing a constant live feed?

With ignition off and engine running, if I slightly depress the clutch the engine will also cut out, however after a few minutes the low oil and battery warning lights come on along with power to cigarette lighter.

Any help greatly appreciated, I’m a bit of a newbie when it comes to electrical systems!!!!

Stew, if new to car electrical systems it's really worth reading up on 1. how they work, and 2. how to repair them. The good news is that once one has grasped the basics of car electrical systems they are very, very easy to repair. There are some great books to read and with Christmas fast approaching you may well ask for Santa to drop them in your Christmas Stocking or under the tree...!

search on Amazon/eBay...

Automotive Electrical Manual (Haynes Automotive Repair Manuals)

The Haynes Manual on Practical Electrical Systems

Classic Car Electrics: Enthusiast s Restoration Manual

Now, your description is a little vague and I think you're getting various functions confused which will lead you down a never ending path. Concentrate on the fault in hand which appears to be an ignition fault. Start with making sure all your electrical connections are spotlessly clean and when you pull each each wire check for continuity off cct, this proves your wiring is good. Then, starting from ignition switch output [o/p] re-connect and check for 12volts along each cct, [Make sure all your earth connections are spotlessly clean and checked to prove you have no high resistance between your earth wires and body, your volt meter/DVM must show zero ohms], continuing until you don't read/find the point where there's no 12volts. This can also be done using a 12v test light. [I prefer using a meter/DVM as this keeps in practice at using the meter].

Other faults will occur when 1. a cct breaks down under load, and/or, 2.there's an electrical short between two non-linked ccts. When this happens look for obvious shorts, poor condition wiring and methodically disconnect any potentially shorting ccts until the fault disappears.

Electrical faults an be very frustrating to find...the trick is to be patient, work methodically...making notes if necessary...and have plenty of tea/coffee and biscuits to hand. I can recommend chocolate Bourbons

First port of call on any mature vehicle is the earth straps - especially on a LR - they are so well know for going tits up, and so easy to replace that it's daft not to...

Your local HGV / Tractor spares place will have them on the shelf - and it does not hurt to add one in to the mix...(ask me how I know )

Also, if you have a cable operated handbrake, make damn sure the earth straps are in good order, as, if the handbrake cable becomes the earth return, then it will weaken it, with potentially disasterous results....

Once the earth returns are perfick, then do as post 2 - including the chocolate bourbons

Earth.i had that once. Flashed lights and radio would go off. Fixed it by removing radio.;-)

mick the builder said:

Earth.i had that once. Flashed lights and radio would go off. Fixed it by removing radio.;-)

Click to expand...

+1 - It's ALWAYS the earth return. Donkeys years ago, new Mk1 fiesta, wipers would start on their own, and lights would be like a disco - it was the engine earth strap had fallen orft due to Fords lack of QC....