D4 Intermittent non start

**gavinwibrow** · 13th December 2021, 08:37 PM

Its happened a few random times over the last couple of weeks to the D4 - MY16 TDV6 and just hit 69K km.

Hop in the car, hit the start button, all the dash lights come on and a couple of seconds later everything goes dead. Read faults on GAP Tool - none found.

Only way to get going so far is (I think) is to switch off/lock up for a couple of minutes then restart and she fires and off we go as if nothing was wrong.

Off to Dazza on Thursday for pending pre Sydney and back? service, and any prior experience/thoughts from the wise would be appreciated - surely can't be something as simple as the brake switch?

Cheers

**Tombie** · 13th December 2021, 09:13 PM

Brake pedal/switch not pushed enough or starting to play up.

Nothing too fancy.

**DiscoJeffster** · 13th December 2021, 09:37 PM

Originally Posted by Tombie

Brake pedal/switch not pushed enough or starting to play up.

Nothing too fancy.

Not convinced. If the start/stop button is pressed and the brake pedal switch isn’t triggered, the ignition stays on - It doesn’t turn itself back off again as described without you pressing the start/stop button again. So unless the OP isn’t clearly describing the behaviour, I think it’s a different issue.

**Tombie** · 13th December 2021, 10:11 PM

Originally Posted by DiscoJeffster

Not convinced. If the start/stop button is pressed and the brake pedal switch isn’t triggered, the ignition stays on - It doesn’t turn itself back off again as described without you pressing the start/stop button again. So unless the OP isn’t clearly describing the behaviour, I think it’s a different issue.

No, if the button is done sans pedal it’s a simple power up.

If an engine start sequence is started and the brake switch isn’t quite connecting or is early released during the press cycle it will power up and shut down again as the sequence fails.

**Macadamia** · 14th December 2021, 02:43 AM

I vote brake pedal switch. Mine does similar to what you describe if the brake has been pumped with the car off so it’s firm and doesn’t get enough range of moment to properly depress the switch. Have to really stomp down on it.

**BMKal** · 14th December 2021, 01:58 PM

Yep - I'll go with the brake pedal switch as well. Mine did exactly the same a bit over a year ago. At the same time, I was seeing a few other random faults. I had a spare brake pedal switch in the glove box, so I swapped it out and all of the problems disappeared and have not returned.

I still carry a spare brake pedal switch in the glove box - they are cheap from any FORD dealer. Can't remember who it was who told me about keeping one of these spare in the car - I think it might have been when I was over at Melrose a few years back. Bloody good advice though.

**DazzaTD5** · 16th December 2021, 05:40 PM

Sorted.

It was the owner, clearly soft weak leg muscles, poor old fellow.

But... I replaced the brake switch anyway and all seems well

P.S and $20 for a OEM which in this case means a FoMoCo one with the "FoMoCo" removed off the back of the switch. Made in Malta

**discorevy** · 16th December 2021, 07:06 PM

Originally Posted by DazzaTD5

Sorted.

It was the owner, clearly soft weak leg muscles, poor old fellow.

But... I replaced the brake switch anyway and all seems well

Too unkind Dazza, hopefully he still has his sense of humour and thick skin

**gavinwibrow** · 17th December 2021, 12:01 AM

Originally Posted by discorevy

Too unkind Dazza, hopefully he still has his sense of humour and thick skin

I hope so too! Actually, all is well Craig, and car is running well again. Amazing that $20 worth can cause so much angst.

**Gravy** · 17th December 2021, 04:05 PM

Originally Posted by BMKal

Yep - I'll go with the brake pedal switch as well. Mine did exactly the same a bit over a year ago. At the same time, I was seeing a few other random faults. I had a spare brake pedal switch in the glove box, so I swapped it out and all of the problems disappeared and have not returned.

I still carry a spare brake pedal switch in the glove box - they are cheap from any FORD dealer. Can't remember who it was who told me about keeping one of these spare in the car - I think it might have been when I was over at Melrose a few years back. Bloody good advice though.

Interesting that these Brake Switch failures are a duplication of occurrences that occur with the 1950s MG TF and TD classics. The work around that resolves the issue is to install a relay that the switch energises. Add a diode across the relay coil and failures are done and dusted.

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