Non starting Defender 300 Tdi...does now?.

Ok...so I turn the key ...and nothing!!!
Starter doesn't even click or clunk let alone turn.
Immobiliser seems to disarm ok on the key fob.
Checked battery.. 12.5 volts...so all good.
Check solenoid and no power when key is turned.
Check starter relay..all good. (swapping technique)
So I make up a cable run it from back of relay to the solenoid...removing existing black wire and it starts!!!

Not quite sure what the implications of this are??
Not quite sure what I have bypassed?

Starts every time and immobiliser seems to function.
Can anyone please shed any light?
Thanks in advance

Black wires are earth leads. Sounds like the connection needs cleaning.

Dodgy ignition switch?

Ignition switch is fine...it starts with bypass wire..
Black wire = earth?.. Well yes sometimes for sure. Br my wiring loom is full of black wires and they are not all earths.

Maybe an immobiliser issue???

Someone must have had this??

Clemmo said:

Ignition switch is fine...it starts with bypass wire..

So how does that eliminate the ignition switch?

Maybe an immobiliser issue???

Yes it could be the alarm spider gone pete tong.

Someone must have had this??

Click to expand...

Yes but you need to eliminate the obvious before you start re-wiring things for nothing. Start with checking the 'crank' feed at the ignition switch. If there is no crank signal from there it is the switch. If the signal is there but getting no further it could be immobiliser or ignition relay. I take it you have also checked the large fuses in the engine bay (passenger side near the bulkhead)?

Yup ...fuses all fine.
I'm still running with my "bypass wire"
Still don't know what I've done.
Just know it runs.

Would love to know the implications??

Looking at wiring diagram for 300tdi, the (black) wire you have bypassed at the relay goes via 6 and 10 of the immobiliser unit then to the starter motor, again via a black wire. I don't have a 300 tdi, so unsure whether you can get at the immobiliser terminals and bypass them there and see if that helps localise your problem.'

Hi,

I have had similar problems but with less knowledge. i bought my land rover 300tdi 110 from a guy who said that the 'reason there is a black wire running through the bulkhead is because it wouldnt start.'
thats fine untill after 3 months it started to... not start.

then it got better by itself for 6 months!..... now just today it has decided it doesnt want to start again.....
if you have any other ideas, or if this thickens the plot further thanks and sorry!

Mark