Internet diagonosis of car problem!

My car has been behaving perfectly, until I get into it this morning and...nothing!

Battery charge all good, lights coming on etc. But when you turn the key, just a 'clunk' and nothing else...not turning over at all...

Any ideas? :rolleyes:

rats? []they love to chew the important bits! Other than that I dont know any thing about cars[]

Starter motor. Possibly check the big cables that juice that beast, if they have come loose then it can't get the current to even turn over.

The starter also may have locked up, and sometimes a knock on the right place can fix it.
So can putting the car in gear, then giving it a shove. This engages the motor to the starter, rotating it a little, which might free it.

Is it manual, and can you crash start it?

My car (1991 Nissan Primera) does this occasionally. It is the starter motor. My dearest fixes it. He showed me how once, but it went over my head a bit. I think it involved tapping the starter motor with something.

Putting it in gear and rocking it was the first thing I tried, wyseyes, no joy...

The battery terminals are a bit salted up and when I have a mo I'll give them a clean just in case...

Yup, I agree with everyone else, the "Clunk" is the starter solenoid pushing the starter gear out to engage with the teeth on the rim of the flywheel. from there the power funs from the battery to the baseof the solenoid casing, the solenpoid plunger going forward also pushes a big flat copper flange on the plunger into the base of the solenoid casing connecting the contacts from the battery to the contacts to the electric motor of the starter motor. From there power runs through the motor coils and earths back to the battery via the block and a heavy cable connecting the engine block to the car chassis and another cable conecting the chassis to the battery negative terminal.

Three possible problems with yours,

1) The electical contact bolts shook loose and the starter motor isn't getting a good enough connection to draw sufficient power to turn the electric motor over against the resistance of the petrol motors inertia.

2) the solenoid plungers copper flange has worn or warped and is not making even contact with both electrical contacts inside the starter motors solenoid casing.

3) The battery is on the way out, gettign tired, and produces enough amps and volts to power lights and EFI etc to get it all started so the alternator can take over the main load, but not enough grunt to get the starter motor moving. Lights are around 55W a bulb on high, rear lights, side lights, indicators, much less. EFI draws between 40 watts and 150 Watts dependant on model and sophistication, so a car can run comfortably on 500 watts, A starter motor is more along the lines of 1500 watts, about three times the draw. So enough juice to run the lights and guages is not nessesarily enough to run a starter.

4) Starter motor electrical wires or brushes have worn out or broken. Unlikely, but lemons happen.

Ta all, did my Girl McGyver bit and got the battery connections disconnected and cleaned up, but no good. AA is now booked to come out - good I managed to get my replacement card so quickly! - waiting time 75 minutes but I am inside in the warm with unlimite cuppas and no pressing appointments, so at least that is not a stress!

Phew, 'twas simply a battery on its way out, enough charge for lights to come on, not enough to start the car. All fixed now, yay AA!

New battery, or a boost start?

Boost start to get it out of the garage, then a new battery. The old one had done me for 3 years, time flies []

Great news, thats not bad for a battery to-day 3 years. Makes being in the AA pay for sub when that happens:)

So it was option 3 then? 3 years is pretty good for a normal domestic car battery.

My van had the original one I bought it with, not sure how old that was, when month before last it wouldn't start. Was option 3 as well, given I've had the van 4 years and it wasn't a new battery when I bought it, that wass pretty good going.

The hilux on the other hand, had option 2 go wrong I had to switch solenoid plungers between the new (secondhand ex trademe) starter motor and the old broken starter motor.

Strangely enough, hubby's Hilux battery went the other day too - after 4 years!