Help needed, car not starting no power to starter motor

[s2_bo]

Hello,

Well after a lot of work and help i finally finished putting one of my s2's back together.

After it was all done it started first time etc and runs fine.

Its just been MOT'ed and didn't fail on anything which i was dead chuffed about.

However after they MOT'ed it the car wouldn't start anymore, so they pushed it on the forecourt.

Basically you turn the key after neutralizing the immobilizer and ignition lights come on, volt meter reads 12V but then on the next click, the one that normally starts the car nothing happens at all.

I jacked it up and measured the voltage at the red cable on the starter motor after giving it a smack with a hammer to see if it needed freeing up (the motor that is).

It only reads:

0.00V when ignition off
0.15v when ignition on
0.10v when you try and turn it over.

I cleaned the connectors so that's not the problem. Anyone know what it could be?
Im thinking ignition switch? Is there a way to test these at the back of the connector block to check voltage? i.e. what pins out put power to the starter motor.

Any help would be greatly appreciated as always!!

Thanks in advance.
Bo

[merlin's S4]

Are you sure it's not an immobiliser problem? You could try disconnecting and re-connecting the battery and trying again!

[Acidburn]

and covering the sensors like sonic did with his.

could you try either bridging the starter (you'd get a few sparks but would tell if the starter still works when it kicks in) or swap it for a different one.

when you go to crank it does the volt gauge still read anything, mine's had battery problems lately in which everything seems fine except the gauge goes down to about 8 whilst the dash lights are still fine, you could try a jump start or bump start to rule out those.

[s2_bo]

I don't think it is because when the immobilizer is on you don't get any power at all when you turn the key. Only once its disabled do you get power to the dash etc.

Unless its a two stage thing where it disables power to the started motor separately.

The only other thing i changed was the ECU, but that shouldn't effect the starter and it was working after i changed it.


If the ignition switch was damaged would it still flow 0.15v to the starter motor??

[s2_bo]

could you try either bridging the starter (you'd get a few sparks but would tell if the starter still works when it kicks in) or swap it for a different one.

How do you mean? Just run 12v to the starter?

I have a couple of spare starters but i think that the voltage is the problem here as the feed is not giving nearly enough power.

[denniselbows]

bo what voltage does the battery show when you try and start it does it still give out 12 volts and what is the red wire at the starter motor? power feed from battery or power to exsite the solinoid.

[s2_bo]

bo what voltage does the battery show when you try and start it does it still give out 12 volts and what is the red wire at the starter motor? power feed from battery or power to exsite the solinoid.

Not sure on the voltage when you try to start it, ill have to check that tomorrow.

The red wire is the one that feeds power to the starter i presume, the only other one connected on there is the earth, they both attach at the back of the heat shrink wrapped part of the starter.

Cheers.

[s2_bo]

I might try this tomorrow, that would then rool out anything but the switch:

Get me home mode - I removed the Ignition cables from the back of the switch and ran two small cables from the fat black and the red and black, popped the block back on, touched the two temp wires and started the engine.

120miles later arrived at home safe and sound.- No way to turn off the engine except to remove the Ignition cables from the back of the switch.

[urquattro-island]

hi

did you take of the little wire going to the starter, if it does not show 12volts, when key is turned fully, you have a lead problem. Wire could be broken somewhere, bad earth, or fuse. It will always show 12v regardless of imob. or not.

[Knight Rider S4]

The red wire is the one that feeds power to the starter i presume, the only other one connected on there is the earth, they both attach at the back of the heatshrink wrapped part of the starter.

I will go with a earthing problem on this..or the small blade connector to random for other faults i think

[220bhp]

There are two spade connectors on my starter,I had mine the wrong way round and the starter did not work, tried the other one and it worked.I think its the top one.

[Flat on my back]

.

Sounds like the solenoid is not switching 'in' when you turn the ignition on. It's the solenoid that sends 'power' to the stater motor.

A gentle tap with a hammer quite often 'un sticks' a dodgey solenoid. But if the solenoid is not getting +12v from the ign. switch you have a wiring or switch fault.

[s2_bo]

Hi Guys,

As always thanks for all your input.

I went back to the car this morning and tried a diffrent battery, still the same story so i "hotwired" it as per GeorgeS2UK's instructions and the starter engaged and the engine started straight away.

So its a switching fault i think.

Im now after a Ignition Barrel, Switch and key if any one has that for sale?

We did manged to drive the car home with out any issues as i fitted a switch to the Black + Black/Red wires so the car now starts by turning key to ignition and then flicking the switch on for a couple of seconds.

Thanks for all your help and please PM me if you have the above kicking around.

Cheers.
Bo

[Acidburn]

Glad you got it sorted, you tried sal yet for the switch if not I think spink has one.

[s2_bo]

Glad you got it sorted, you tried sal yet for the switch if not I think spink has one.

Thanks mate!!