Immobilizer weirdness (Defender 110 300TDi)

Jan 08, 2010 4 Replies

Wotcher chaps, an odd one this. My starter motor wasn't firing, so I checked the 12v permanent feed, that was live, I checked the signal cable from the ignition switch, that was fine too (0v normally, 12v when ignition turned). But nothing from the starter, no solenoid click, other than the relay in the cab.



So I put a new starter in, that also didn't fire, when I changed the immobilizer key it fired up straight away!



So am I missing something, or did I have a dual problem of the first starter being iffy and the immobilizer key also being iffy? I can't see how the immobilizer could stop the first starter firing if all the right voltages were there, there's no other connections on it, just the permanent feed and the signal wire.


How are your Earths?

Test the old starter with some jump leads.

Lee

Slightly puzzled as to how that would affect things, the earth to the starter is via the bolts. No other electrical problems to speak of.

I would do but the new starter was obtained under an exchange scheme, it would have cost me an extra £25 to keep it and as it was getting sticky anyway (sometimes I would have to keep the key turned for a few seconds before the starter would fire) it didn't seem worth keeping. It probably only needed a new solenoid but the new starter does spin the engine faster.

I think he is primarily thinking about the earth strap between the engine block and the chassis/battery. But, like you, I can't make a connection with your specific issue.

I asked about the earth as Ian mentioned a dual problem potential. I would imagine the issue is with the immobiliser key.

I only mentioned the earth as everything else that is required to make the starter work is present and correct.

The earth cable braid clearly gets some fatigue and as the starter is under more load in these tempretures and as such it is possible that any weak link if it were to be the earth could give the same effect as a huge dry joint.

Like I say.. not suggesting for one minute that it is the cause .. but it is worth checking if the problem hasn't gone away "long time".

Lee D

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required