Starter Solenoid just clicks, despite changing everything

[rxl123]

Hi Folks,

Help really appreciated here. I am being driven (or not) to distraction by the failure of my S3 petrol to start. Symptons are that 99 times out of 100, when I turn the switch, the starter solenoid just clicks. On the 100'th time it will spin the engine, and when it starts I can then stop the engine, start it again and the starter still works. I can leave it a couple of hours and then it still works, but if I leave it overnight, back to clicking only again.

Here's what I've done to diagnose.

Tried it on the jumps, and replaced battery, same behaviour. So it isn't power.

I thought it might be the starter motor so I replaced with a shiny new one, but same behaviour.

So for a tenner I thought I'd replace the starter solenoid, but still the same behaviour, works just 1 in a 100 ish times.

Tried hooking the starter motor direct to positive and negative on the battery, to eliminate any of the wiring circuit but no sign of starter turning.

Tried to identify if the starter circuit was working ok by putting a test lamp across the live heavy cable to the starter motor, and to the body of the starter, and as you would expect, the lamp lit when the key turned.

Even thought it may be a dodgy earth and tried removing and replacing that, but still the same behaviour.

So where I am at now is that the electric circuit seems fine, as proven by the test lamp. The starter works fine as have taken it out and bench tested it. Battery, solenoid and starter are all new. I can't hear any sound at all from the starter trying to fire, and maybe the dog catching on the flywheel.

The truck stood up in a field for 6 months without being started,and before it was parked up it all started up fine. When we tried to start it, this sympton was then happening, so it is probably something that has occurred while it was standing.

All I can think is that the flywheel is being restricted somehow, by a seize or a partial seize. On the 100th time when it does spin, it spins slowly and pretty noisily, and gradually gets quicker. When it is running the clutch engages and disengages fine, and all gears drive. The clicking happens whether I have the clutch depressed or not. So if it is a restriction on the flywheel preventing it turning, it happens even if the clutch is in, so I'm guessing it means if there is a seize stopping the turn that it is the gearbox / transfer box not the engine as it is isolated by the clutch being depressed.

Sumamry - I can't think that it would be electrical as the test lamp lights when the key is turned. All the parts are new, so it must be the flywheel being prevented from turning. But the clutch works fine.

Any suggestions as to what to try next really gratefully received as I am out of ideas. I am a basic level diyer only so stripping a gearbox is beyond me, so guidance really appreciated!

Thanks all.

[Snagger]

It's not a seizure. The fault is electrical. Try mounting the solenoid the other end up - maybe gravity will help the slug make contact rather than fight it. However, if connecting the battery directly to the starter did not turn the starter, you have either a fault in that cable or the earth. Try running a second earth from one of the starter motor mounting bolts directly to the battery, bypassing the braided strap, chassis and old battery cable; there are many contact points there which corrode or get too dirty and cause trouble, and they are the usual source of problems like yours.

[lexi]

I have found this is best way to earth the starter. Good cable from battery earth to the bottom of the heavy carrier. I also have another from same battery terminal to inner wing. From the battery carrier take another really heavy lead all the way round to to starter lug at bellhousing. From there another to chassis.

That makes a huge difference if you have any sluggish starting.

[rxl123]

Hi old hand and Lexi,

Thanks for your comments. Would make these as permanent additions to the wiring or just as a fault diagnostic in this case?

Thanks

Gary

[Snagger]

I would make them permanent - the standard earth system is very prone to corroding. I have done the same on my RRC - they (and Defenders and Discoverys) have similar problems, and when the earth strap deteriorates, the starter tries to earth through the hand bake linkage (so do Series). For a Sereis vehicle with its sturdy hand brake link system, not much happens, but the coilers have relatively puny Bowden cables for their hand brakes; the cable's teflon coating melts, jamming the cable in its outer sheath, locking the brake on. It gets a bit smokey, too...

[ejparrott]

Permanent, deffinately permanent. You can't have enough earths, I've just run anew earth from the rear clusters back to battery in Kettle, the lights work so much better.