No crank No start

[C4V V6]

Hi been a while, I've got a problem with my V6 not starting, food all the usual tests, had starter off and that's fine have power at ignition etc and narrowed it down to wire between ignition switch and starter solenoid. Question is, is there a starter relay? Or is it just likely to be a break in the wire as it makes its way through the engine bay to the starter? Thanks in advance

[Robsey]

I have looked in the V6 college manual and on Haynes.
None show a starter relay for petrol engines.
Only for diesels.

So - unless you have a starter inhibit relay fitted as part of an anti-theft system, you should have a direct link from the ignition switch to the starter solenoid.
A 2.5mm black / red wire.

Are you sure it is a wire issue, or could it be burnt contacts of the ignition switch?.

[C4V V6]

Thanks for quick response .

[vexorg]

I would say ignition switch, you can check the back of the switch with a meter and check for continuity or if getting 12v out.

[chrisp]

Forgive me if I'm stating the obvious, but have you checked the battery? I had this same issue with my V6 a year or so ago. I'd parked it after a run with no problems and then when I tried to start it 2 days later - nothing. I also started looking at fuses, wire continuity, relays etc but then just on the offchance tried the horn and the headlights - completely dead. It seemed that the battery had died completely virtually overnight and I've noticed that this happens with modern batteries. In the past they used to get progressively feebler so you had some warning of them completely failing, but this doesn't happen with modern batteries. Anyway, a new battery completely fixed the problem.

[C4V V6]

I would say ignition switch, you can check the back of the switch with a meter and check for continuity or if getting 12v out.

Checked ignition switch that's fine. Cheers

[Robsey]

All the obvious stuff for someone who knows how to test the ignition switch.

So... if the ignition switch is good,
Is the battery good?
Then there are the grounding straps / braids.
I am sure you know where they are.
Should be either the gearbox end plate or one of the big bolts on the bell-housing.

Beyond that, you need to check the fat red cable between the battery "+" and the starter.

Goes without saying check that all cables connectors are clean and securely fitted.

Same with the black / red solenoid cable connection.
Clean, dry and securely fitted.

Your could check for voltage at the solenoid connection when turning the key.

[vexorg]

Or if it's an automatic then it has an inhibitor switch.

Is it completely dead when starting, do lights dim, or clicking.
Any aftermarket immobiliser?, mine completely kills the ignition if immobiliser is active.
Check the battery voltage when trying to start.

How did you test the starter? There are two parts to them, the solenoid anf the motor. The solenoid acts like a big relay for the motor, if the solenoid is bad then it wont start, but if you put 12v one the motor connection at the back of the solenoid then it will run.

[Robsey]

To test the starter.
Being very careful.

Use a sturdy jump lead.
Connect one crocodile clamp securely to the bolt with the black / red solenoid wire on it.
Ensure the crocodile clamp is not touching the starter motor body, or the engine / gearbox casing.

Touch the other end of the jump lead to the red "+" battery post of the battery.

Any of three things may happen.

1 - Nothing happens. Either faulty starter solenoid or defective grounding of the starter motor.

2 - The solenoid clicks loudly.
The solenoid is fine but it is either not enough battery voltage to spin up the starter, or the starter motor is jammed or duff.

3 - The solenoid operates the starter, and the car starts cranking. The problem lies in the supply voltage to the starter motor from the ignition switch.
This then leads back to the ignition switch or an immobiliser relay (aftermarket alarm) or wiring between the switch and the starter.

One other thing may happen if you failed to ensure the crocodile clamp is not touching the starter motor body, or the engine / gearbox casing..
You may get a vigorous fireworks display from the jump lead

[C4V V6]

To test the starter.
Being very careful.

Use a sturdy jump lead.
Connect one crocodile clamp securely to the bolt with the black / red solenoid wire on it.
Ensure the crocodile clamp is not touching the starter motor body, or the engine / gearbox casing.

Touch the other end of the jump lead to the red "+" battery post of the battery.

Any of three things may happen.

1 - Nothing happens. Either faulty starter solenoid or defective grounding of the starter motor.

2 - The solenoid clicks loudly.
The solenoid is fine but it is either not enough battery voltage to spin up the starter, or the starter motor is jammed or duff.

3 - The solenoid operates the starter, and the car starts cranking. The problem lies in the supply voltage to the starter motor from the ignition switch.
This then leads back to the ignition switch or an immobiliser relay (aftermarket alarm) or wiring between the switch and the starter.

One other thing may happen if you failed to ensure the crocodile clamp is not touching the starter motor body, or the engine / gearbox casing..
You may get a vigorous fireworks display from the jump lead

Ha ha yes had starter off fully and checked it on bench. Also had it connected like stated but off car and run a wire from ignition switch to it and it engages as it should. Even more making me think it's a brake in the wire to the starter. Used test light and multi meter on ignition switch also etc.

[Robsey]

Okay then...
Obvious solution is to run a stout wire from the ignition switch to the starter.

Or if you prefer, run a wire from the ignition switch to a relay in the engine bay.
It would shorten the distance for the voltage to travel.
And therefore reduce voltage drop - giving more ooomph to the starter solenoid.

Battery to solenoid... all of about 70cm travel.
rather than, battery to switch, back to the engine bay to the starter solenoid. Probably 300 to 400 cm travel.

Black / red from ignition switch (terminal 50) to relay pin 86.

Brown wire from relay pin 85 to the inner wing or battery "-" (negative pole).

2.5mm red wire from battery "+" to relay pin 30.
Or better still - from the fat red on the starter motor to relay pin 30.

2.5mm black / red from relay pin 87 to the starter solenoid.

The closer the relay is to the starter, the less voltage drop and more oomph to the solenoid.