Starter Motor Problem

[alan wheeldon]

Bit of a strange one

I have been checking my air hoses today to make sure all the clips are nice and tight as I have a problem with the car stuttering on boost. They were all fine so I put everything back together that I had removed, including parts around where the starter motor is.

Thinking everything should now be ok I went to start the car. With the key in the ignition, and turned to the ignition on (position where your dash lights come on) the engine started to turn over.

At this point the engine should not be cranking over until you turn the key to the next position so something is wrong?

I removed the main +12V cable to the starter motor and all is back to normal with the key positions and the dash lights work as they should but obviously the car will not crank over due to the starter disconnected.

I have checked the starter relay and that works as it should.

So I have this strange problem. And don't know what to do now, would the starter motor be faulty or could this be an electrical problem. Perhaps I knocked or blew something when I was checking my hoses around that area?

Any ideas guys??

[Leakie Tbar]

Have you got 12v on the ignition feed when youre turning the key ?

Have you got B+ 12v to the main starter cable ?

Get your multimeter and check for earth on the starter casing solinoid and body of the starter

try getting a earth jump cable mount it from a good engine earth point and put it to the starter then try and crank, This normaly rules out earth volt drop

[alan wheeldon]

Have you got 12v on the ignition feed when youre turning the key ?

Have you got B+ 12v to the main starter cable ?

I'm not sure how to check that, there are 3 cables connected to the starter motor, one is a push on clip and the other 2 are together on one bolt. Is the ignition feed the same cable as the main starter cable ie. the push on clip?

[Leakie Tbar]

the push on clip mate the thick cable is the battery positive

have you got a multimeter?

[alan wheeldon]

Yes I have one. So remove all the cables from the starer and then test the end of the cables to see what I have right??

Would i be right in saying I should have 0V on the starter connector when the key is in the on position until I turn the key to the start position where I should then be getting 12V

[Leakie Tbar]

no mate leave them connected

12v at main thick cable held on with a nut yarp ignition on


disconnect the plactic clip thinner wire the one underneath
you will need help hold positive of multi meter to the wire side connector
and negative to a good earth point get someone to crank the key
you should see 12v thats the ignition feed

dont forget to check and recheck your earths

[toxo]

Starter motor triggering can be caused by missing one of the big earths from the car, like the inlet manifold or gearbox one.

[alan wheeldon]

Ok I'll check that when I get home from work

[alan wheeldon]

Ok this is what I've found.

Main positive terminal on the starter. I have 12V constantly with the ignition off, on and at start. (which I believe to be correct?)

Small plug on connector on the starter. 0V with the ignition off, 12V with the ignition on, 12V with the ignition at start.

But.... When I then let the key go back to the on position I have 0V, turn the key again to start and I get 12V back. Let go of the key back to on position and again back to 0V.

That is what it is suppost to do I believe but I have the initial problem of at the first attempt I get 12V at the on position when I should be getting 0V. This is causing the starter to be constantly on.

What now???

[Leakie Tbar]

Main positive terminal on the starter. I have 12V constantly with the ignition off, on and at start. (which I believe to be correct?)

this is ok

Small plug on connector on the starter. 0V with the ignition off, 12V with the ignition on, 12V with the ignition at start.

this should only be 12v when you turn to start


ok so let me get this straight the starter motor is TURNING THE ENGINE OVER IN IGN ON ??? is the engine turning or just the starter??

multimeter time remove steering cowls go to the ignition switch we are looking for red wire thick pin 1 of the switch on the back of the switch we should only have 12v on start if we have 12v on ign on the switch is fooked

[alan wheeldon]

ok so let me get this straight the starter motor is TURNING THE ENGINE OVER IN IGN ON ??? is the engine turning or just the starter??

The engine is turning over so this must mean that the started motor is working as it should right and the problem is an electrical issue?

Like you said, I'll try and check the ignition switch next

[Leakie Tbar]

any news yet?

[alan wheeldon]

Ok i have just checked the continuity of the switch according to this chart



All is as it should be so I assume the ignition switch is working fine so I must have a problem elsewhere??

The Starter Relay has also been checked for continuity and is all ok.

I have also tried putting a wire from the starter motor straight to the relay to eliminate the wiring loom in that section and still the same problems.


So..... Things checked and belived to be ok:

Ignition switch ok
Relay ok
Starter motor ok
Wire from starter motor to relay ok

Remember this problem only started after I was messing about in the engine bay Starting to do my head in now! Where are these earths I need to check?

[alan wheeldon]

Oh and i can't find the red wire you were talking about closest thing was a thick black and red one



The wire on the starter motor (belive this wire to be called Terminal 50) is black/white

[alan wheeldon]

Ok both problems fixed now

The issue with the starter was the earth wire from the engine loom to the back of the inlet manifold. When the new engine was fitted the wire was not bolted on and was just hanging and only just touching the manifold. When I was checking all of my air pipes for leaks I must have disturbed this wire and pushed it away from the manifold where it was just touching. Now it is bolted in the proper place all is fine with the starter issues

The initial problem with the stuttering on boost was down to the one way valve from the inlet manifold to the map sensor. This was put on the wrong way round.

All in all two simple mistakes which caused one big headache !

Thanks for all your help

[toxo]

Starter motor triggering can be caused by missing one of the big earths from the car, like the inlet manifold or gearbox one.

The issue with the starter was the earth wire from the engine loom to the back of the inlet manifold.

I love being right