Signs of a weak starter motor

[RossK]

Testing the wires isn't hard.
First check the voltage of the main starter lead, it should be whatever you battery voltage is. 12.6V is pretty typical.
Grab the main lead and shake it, whilst measuring the voltage - did it change? It shouldn't
Remove the trigger wire from the solenoid and do the same test - you'll need to have someone turn the key.
Then set the multimeter to read resistance and do the checks again.
I got hugely varying voltages and when i shook the the wire, the voltage on the trigger wire would sometimes drop to 0V - this is your no crank scenario.
Resistance also varied when shaking the wire, from 0 to off scale.
When i removed them I checked them again on the bench and got the same results - ie it wasn't just poor connection or dirty terminals. I actually cut the cover off some of the main lead and you could see broken strands of copper wire. The wire was very stiff and made cracking sounds as you flexed it.
I replaced them over 2 years ago and it's been fine since.
I'm not saying this is definately your issue, but it's not hard to test to eliminate the possiblity.

 

[wannaeatyourbrains]

Thanks. This is the kind of really helpful and practical advice I like to get from people here. Much appreciated.

 

[wannaeatyourbrains]

OK you bloody rippers. With your good help and a bit of that bus cable...

That very annoying issue has finally been solved.

I should have gone the full Monty and changed that wire before. In retrospect it is no wonder that weak spindly little thing on there from the factory buggers out. I thought it was supposed to be hot for sure cause it is so small.

Now I got a man-size current happening. It loves it.

 

[Fu Manchu]

@wannaeatyourbrains, you continue to impress me with the most ghetto sht ever.
#Resourceful

 

[wannaeatyourbrains]

I was stoked the short bit of cable was long enough, so I can sell the long bit to the next guy wants his car fixed, ha ha.

 

[vc commodore]

I was stoked the short bit of cable was long enough, so I can sell the long bit to the next guy wants his car fixed, ha ha.

Great to hear your problem is solved....Love your recycling tip too....Onselling to cover labour costs

 

[TwoUpTourer]

Belated response I know - been busy! But today I fixed it.
How anyone can change over the starter motor without removing the manifold and a pile of other stuff I don't know, but at least I got the metal shield off with tips offered here, and found that the nut securing the main supply cable to the starter was not very tight. I removed the nut, cleaned it and the metal tag on the cable, did the nut up as tight as I thought I dared, and now voom!
No more half arsed groaning into action

What was very worrying is that while I was down there near the auto transmission pan, I saw a bolt was missing. Odd I think, so I put a socket on one of the others only to find it not even finger tight! In fact all of them were loose, plus another had fallen out the back! No wonder there was seepage from the pan. Found a few spare bolts in my collection and now all good. Oil is way low, so off to get some Dextron III.
But a lesson to all - go and check your tranny bolts to be on the safe side, particularly if you have any seepage at all.

Many thanks to contributors who pointed me in the direction of the cabling rather than the starter as being chance of being the source of the problem.