2004 Fab starting issue *HELP*

[MHPhotography]

Hello all! 

 

I have a 2004 fabia at work the energiser wire is constantly live at the starter motor end. But... at the ignition switch it only becomes live when cranking, as it should! 

 

Also where is the starter relay?  

[Breezy_Pete]

I don't think there is a starter relay.  Isn't it just fused permanent 12V (red) into ignition switch, red/black wire out of ignition switch to starter solenoid 'terminal 50'? (Thinnest wire at starter motor).

Which engine does this car have?

Edited 12 January, 2016 by Wino

[MHPhotography]

hi its a 1.2 htp azq

Edited 12 January, 2016 by MHPhotography

[Breezy_Pete]

So the wire labelled "Terminal 50 feed" on this photo is constantly 12V? Even when not cranking? Can't be surely?

[MHPhotography]

Hi yes constantly 12v feed when ignition is on, not in crank position, checked the wire at ignition switch end works how it show only live when cranking 

[Breezy_Pete]

So the wire at the starter can't be connected up right, it must be going to an ignition live feed instead of where it should go at the ignition switch??  Can you make a really long lead for your meter and measure continuity to confirm that it isn't the same wire at these two points? Actually that's not really necessary, the measurements you've done already prove that.

Edited 12 January, 2016 by Wino

[sepulchrave]

Not really, the solenoid is a relay remember so when the coil is energised by switching to earth you will get 12V at the key switch while cranking because it's running through the solenoid to earth.

[Breezy_Pete]

Not really, the solenoid is a relay remember so when the coil is energised by switching to earth you will get 12V at the key switch while cranking because it's running through the solenoid to earth.

?

 

As I understand it, this is the circuit:

 

 

The OP is measuring different voltages at A (Terminal 50 of ignition switch) and B (terminal 50 of loom connector to starter)? They're linked together by a piece of wire, so should show rather similar voltages relative to batt neg.?

[sepulchrave]

Then something impossible is happening.

 

On many cars it's the earth that's switched at the key rather than the positive because there is a big permanent live direct from the battery to the solenoid and the solenoid acts as a heavy relay and fires the starter motor whilst moving the pinion into engagement.

[coskev]

Bit of background info needed,has the car come to you with this fault already present?

[Breezy_Pete]

Good call.

Also, what colour is the wire going into that terminal 50 connection at the starter? Does it look like it has been repaired (like the one in my pic)?

[sepulchrave]

Ok, if the starter motor is dead and there's no click then the solenoid must be at fault. Can the car be bump started?

[coskev]

Again,more info required tbh.

As he hasn't stated is the starter running when you turn the ignition switch on?

Or is it as above and it's dead not doing anything?

[MHPhotography]

Background is.. Car wouldn't start, but would bump start. Starter motor had burnt out so was replaced by the owner. It still wouldn't start, so he bump started it and burnt the new starter motor out!! Then he booked it into us (local garage)  and we can't seem to find the issue! 

 

Currently when you turn the key into the ignition position, the starter wires go live and the dash lights turn on. When you turn the key into the crank position you get a crank signal on 50 but 50b is a constant live? 

[sepulchrave]

Faulty ignition switch.

[coskev]

Have you asked the customer if they have tried fixing it with any wiring altered?

Hi yes constantly 12v feed when ignition is on, not in crank position, checked the wire at ignition switch end works how it show only live when cranking

  

Faulty ignition switch.

You think?

Taking into account what the OP says above?

[sepulchrave]

It seems more likely than a DIY rewire, if the ignition switch was stuck in crank then it would burn motors out from being permanently engaged, I've seen it on other cars (usually French).

[Breezy_Pete]

I think I  agree with sepulchrave.  No way 50b (the one that goes to the starter solenoid) should be permanently 12V, it should only be 12V while the key is in its furthest clockwise position. That switch contact possibly got welded closed in that position when the first starter failed?

Edited 12 January, 2016 by Wino

[coskev]

He states above though the wire at the ignition switch only goes live when he turns the ignition key to the start position,it's not live at the ignition barrel in stage 2 ignition but it is at the starter?

[coskev]

Could be a problem in the multiplug to ignition switch?

This would explain why the ignition switch seems to be showing it's working correctly.

[Breezy_Pete]

Thing is, there's terminal 50, which tells the engine ECU that cranking is happening, and 50b which is going to the starter solenoid. The former sounds like it's OK, the latter not. Earlier in the thread, I hadn't realised that, til I looked at a wiring diagram, so where I said T50, I meant T50b. If that is 12V when the key isn't turned max clockwise, it must be a dodgy switch, I think.

Edited 12 January, 2016 by Wino

[coskev]

Ah that will explain it,two terminals supposed to go live when cranking and the OP has prob only checked the one that is working ok

[MHPhotography]

Hi just to let you know it was the ignition switch many thanks for all your help