Car failing to star. Help!

[Phil888888]

I have a 2005 Mazda 3 as a 1.6 petrol with 90k on the clock. The car has a full service history and has literally just been through a full service and MOT. I had a new battery fitted around 3 months ago, so I know the battery is fine.

So I was out yesterday at the park. I go to get in the park to come home, key goes in the ignition, all the dash lights come on as normal.....but then nothing. I turn the key and there is no sound, just nothing. I initially thought maybe a immobiliser issue so I get out the car, lock and unlock again....I go through the sequence again and nothing happens. I try using the spare key but the same thing happens. No turning over, no clicking, just dead.

The headlights all worked fine and the battery is perfect.

I had to leave the car where it was to go work.

The next day I arrange to meet the AA with the car. I get in the car in front of the AA man and guess what, it started straight away.

The AA patrol didn't bother to out on the diagnosis machine. He looked at a wire under the bonnet and said it was probably this that was lose and to next time "give it a wiggle".

I will attach the picture of the wire he said to wiggle. There are 3 wires/connections there but I think it is the one highlighted. (could be wrong). The picture is taken from the front of the car with the bonnet open looking straight down on the front of the engine but behind the fan.


But when I phoned up a mechanic he said the AA patrol was talking nonsense and those wires have nothing to do with the start.

So who do I believe?

What are peoples opinions? Can a starter work one day and not the next then work again the next? I thought if a starter stopped working you would hear a 'click' noise, but I don't recall hearing anything. It was just nothing happening...no noise no nothing.

 

[flameport]

Can a starter work one day and not the next then work again the next?

Yes, particularly if the solenoid is sticking / worn, or the starter motor itself has a problem.

 

[Burnerman]

If that plug is connected directly onto the starter motor (difficult to see) then it indeed could be the fault.
Why not unplug it, check for green debris both in the female and on the male, spray some contact cleaner on both and give it a try?
John

 

[Phil888888]

If that plug is connected directly onto the starter motor (difficult to see) then it indeed could be the fault.
Why not unplug it, check for green debris both in the female and on the male, spray some contact cleaner on both and give it a try?
John

That was a great idea. So I went to the car and disconnected those leads. Guess what. The car still started with those leads disconnected! So what on Earth was the AA on about?

 

[Burnerman]

I’m afraid you’ll have to give us a pic of whatever it is that those leads are connected to.....clearly not the starting circuits!
Connections onto the starter motor itself will certainly cause your issues if they are dirty or loose.
John

 

[DIYspanner]

The solenoid has a thin wire to power its coil and two heavy cables for starter current and they bolt onto pegs.

One of the heavy cables, more a strap really, is about 1" long and its other end bolts on to the starter on which the solenoid sits. The other heavy cable on the solenoid comes down directly from the battery. If either the solenoid wire or the two heavy cables have got corroded or have loose connections, starting the engine will be a bother.

 

[Phil888888]

Yes, particularly if the solenoid is sticking / worn, or the starter motor itself has a problem.

I was under the impression that if the Starter motor was not working you would hear a 'clicking' noise when trying to start. But I heard nothing at all. Do starters sometimes make no noise if not working then?

 

[DIYspanner]

A good video to watch.

 

[flameport]

I was under the impression that if the Starter motor was not working you would hear a 'clicking' noise when trying to start.

If the motor or the wiring to the motor it has failed, the solenoid will click.
If the solenoid has jammed or failed, it will be silent.

 

[Keithmac]

Really you need to be checking for +12v supply AND cranking +12v while it's doing a no-start fault.

Could be the ignition playing up (contacts worn out), wiring fault, starter solenoid fault, poor connection to starter.

 

[ericmark]

Had the same with a Jaguar XE, sat in car press button, nothing, left it for some time and I sat in driving seat instead of wife, and started A1, this happened a few times, and we took it to dealer who fitted new battery, this seemed to cure it for around a year, then started doing it again, called RAC and he actually found the problem, it seems there are two switches connected to the brake peddle, and if you don't press the brake hard enough it works the switch that lights up dash to tell you to press brake peddle so you get no warning to say press brake peddle but it does not work the switch which allows you to start the engine once brake peddle is pressed. And under normal use the vacuum is not lost so very little pressure is required, but when it failed we had been sitting in the drivers seat and must have touched the peddle and used up the vacuum, so have to press it harder.

The RAC man had tried to press peddle with hand and car would not start, then he sat in the car and used foot and it did, so he emptied brake vacuum and yes he was able to get warning message to go out, pressing brake lightly, but would not start, pressing harder on brake and it started, lucky we had kept old battery for caravan, as looking at a £200 battery.

 

[DIYspanner]

I understand the concept of ignition switches via the clutch pedal so you don't jerk the car forwards/backwards if accidentely left in gear but why switches on the brake pedal?

 

[ericmark]

I understand the concept of ignition switches via the clutch pedal so you don't jerk the car forwards/backwards if accidentely left in gear but why switches on the brake pedal?

There is no clutch peddle, it is an automatic, the manual version can't tow as much as the automatic, 1500 manual 1800 automatic likely as an 8 speed auto, the gear selector retracts with ignition off, and you can only select once ignition is on, and it auto goes to neutral or park when it retracts so it does seem odd to have to press brake, and not really anti theft as large sign on dash says press brake peddle.

But it seems not only Jaguar have this, since it happened to us, I have heard other cars have the same, likely some thing to do with ZF gear box.

 

[EFLImpudence]

It stops the car moving when you start it in park or neutral and then put it in drive or reverse.

No - I never use the handbrake.