300tdi Defender ignition problem?

[Grizzly_Adams]

Howdy everyone!

Got a weird one with my beloved Defender.

The other day, whilst the negative was connected to the battery and I was loosening the positive terminal (yes, dumb me) I managed to touch the spanner to the body causing a spark.

After that the car won't start :-D Yay me! No lights on the dash but it would still turn-over.

As a precaution and easy first step, I have replaced every single fuse I can find in the vehicle and I have got a little bit further.

Just to confuse matters a bit, I have a installed a button start. Normally operation is you'd switch the key over to the 'on' position and press the button to start her. Without having the key in the 'on' position the car would turn-over but not start.

Now I get lights on the dash and she will start/run but /only/ if I hold the key in the full 'start' position. If I hold the key in the full 'start' position, the lights come on the dash and when I press the start button she starts and runs fine - however the moment I let the key fall back to the 'on' position the engine turns off.

I am after some constructive thoughts/suggestions on further troubleshooting please :-)

Thanks!

[TonyC]

Hi,
The thing that let's the motor run or stop is a 12V supply to the fuel injection pump, this wire goes into the rear of the pump.

My guess is your not getting 12V to this except in the start position, check for a good connection and voltage on that wire.

Why did you you add the start button? Has the start contacts in the ignition switch died?

I'm guessing the run contacts have also died.

If the short to the body has killed the switch, I'm guessing you have some poor body earths in the car.

Hope this helps

Tony

[JDNSW]

I think I agree with Tony's analysis.

[Blknight.aus]

Its also possibly taken out the main fusible link or connection to, that supplies 1/2 of the fuse box in the drivers kick panel area.

[Grizzly_Adams]

Thanks Tony, I just confirmed your analysis - no power to the fuel injection pump until the key is in the start position. Now to figure out why

As for the start button.. eh, it's a long story, but the TLDR is that I let someone talk me into it.

Hi,
The thing that let's the motor run or stop is a 12V supply to the fuel injection pump, this wire goes into the rear of the pump.

My guess is your not getting 12V to this except in the start position, check for a good connection and voltage on that wire.

Why did you you add the start button? Has the start contacts in the ignition switch died?

I'm guessing the run contacts have also died.

If the short to the body has killed the switch, I'm guessing you have some poor body earths in the car.

Hope this helps

Tony

[Grizzly_Adams]

Its also possibly taken out the main fusible link or connection to, that supplies 1/2 of the fuse box in the drivers kick panel area.

I'll see if I can find that, thanks Blknight.aus

[Blknight.aus]

am currently going through this with a customers toyota,

the internal connection that bridges the ignition to the start position in the switch has corroded away in the normal run position, If you hold the key just either side of the detent, the switch tests ok...

[123rover50]

Hi,
The thing that let's the motor run or stop is a 12V supply to the fuel injection pump, this wire goes into the rear of the pump.

My guess is your not getting 12V to this except in the start position, check for a good connection and voltage on that wire.

Why did you you add the start button? Has the start contacts in the ignition switch died?

I'm guessing the run contacts have also died.

If the short to the body has killed the switch, I'm guessing you have some poor body earths in the car.

Hope this helps

Tony

I bypassed mine and ran a separate feed through its own switch hidden under the dash to the injector pump. Slows down thieves to as motor turns over but wont start untill that secret switch is on.

[Grizzly_Adams]

For everyone interested, it was the ignition switch - the glue that held the connector to the back of the assembly had died.

I tested it by holding the plastic connector hard to the back of the assembly and the vehicle worked fine.

I've purchased a replacement ignition assembly and the car is working (yay!), I just need to get some bolts to hold the ignition assembly back together and put her all back in 1 piece again.

Thanks everyone for the advice.