Engine only stop when lift brake pedal or turn off headlights

[acgmarketing]

Got a good one today .... Turned ignition key of TD5 disco (2000 auto) to off and removed key fob only to have engine happily continue running. Had lights on and foot on brake pedal at time. Put key back in and turned all the way to starter (engine kept going and no starter engaged thankfully).

Tried turning off again ... Same response. Went to get out of car and took foot off brake pedal - engine started to shut down and I out my foot back on the pedal before it stopped and it restarted! (Not starter motor run, was still turning over as put foot back on brake). foot off brake and engine stopped.

I started it again and reconfirmed exactly same response when trying to turn off.

Later when I got home I found that same thing happened. This time with key out of ignition I turned off the headlights (with foot still on brake pedal) and turning off the headlights, with foot still on brake pedal, also shut down engine. I tried the same trick of shutting down and restarting while still turning over using the headlight switch (and foot still on brake pedal) - yep, same as before with brake pedal.

Seems that with brake pedal down and head lights on my car wants to keep running even with key off and removed. Turn off headlights or remove foot from brake pedal and turns off....

Any ideas?

[loneranger]

We had something similar in our Dmax when we had a trailer connected. We suspect it was to do with the trailer plug wiring.

For our camper trailer battery to charge the redarc required an ignition wire so the manufacturer had connected a short from the brake light on the trailer plug to the reversing wire.

So I would suggest it may be an electrical problem. Others with more knowledge may have other suggestions.

[sierrafery]

Interesting one... might be a missing earth somewhere, some questions:
1. when you turn the ignition off with brake depressed or hradlights on and the engine keeps running the radio shuts down or not?
2. if you dont touch the brake at all only lights on it still keeps running?...if yes leave the lights on and engine running, go to the engine bay fusebox and remove relay R9 see if it stops or not

unfortunately this thing is very strange so some voltage measuremets might be needed... Do you have RAVE and a multimeter?

[Justinb]

Exactly same issue I have when trailer is connected to my 93 RRC, and then only occasionally. Have electric brake controller fitted , I suspect the trailer plug is the issue but I'm just guessing, something to do with the power feed to the trailer, whichever terminal that is in the plug. Probably have a fiddle this weekend.
Good luck
Justin

[loneranger]

Try disconnecting the reversing wire to the trailer plug.


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[Pen48]

Hi acgmarketing

Did you find what was causing your engine run problem? Have almost exactly the same problem with my D2 4.6 V8, engine keeps running with foot on brake & key out. Stops when I take foot off brake. No headlights on, trailer hooked up or anything else.

I'm not overly concerned, I'm a Sparky and have rewired a few cars including my '84 RRC with the Lucas 'Prince of Darkness' wiring system. Once I sort it out I'll post a reply here with my findings.

cheers Pen

[sam_d]

Hi acgmarketing

Did you find what was causing your engine run problem? Have almost exactly the same problem with my D2 4.6 V8, engine keeps running with foot on brake & key out. Stops when I take foot off brake. No headlights on, trailer hooked up or anything else.

I'm not overly concerned, I'm a Sparky and have rewired a few cars including my '84 RRC with the Lucas 'Prince of Darkness' wiring system. Once I sort it out I'll post a reply here with my findings.

cheers Pen

More than likely a dodgy earth from the ECU. My Defender had exactly the same problem you describe due to the earth wire being damaged where it joined to the chassis. It wasn't easy to spot but luckily it was easy to fix.