Misbehaving Defender electrics!

Hi folks, wonder if anyone could share some light on my problem.
Shes a 1989 Defender with 200tdi engine and following a period of inactivity she wouldn't start...she just clicked on turning the key so I bought a nice new battery and....she clicks as before.
I then removed the starter, tried it outside the vehicle and it including the solenoid seem to work ok. I put it back together and tried connecting direct positive (by jump lead) to the solenoid and a small flylead to the solenoids small connector which i touched to the positive direct battery and she turns over the engine nicely & if i connect the normal positive lead (only it and not the other cable to supply the rest of the bus) and still my fly lead direct to positive she does the same, turns nicely, BUT BUT BUT connect the other lead (+) that goes to alternator & rest of her electrics, she CLICKS even with my flylead direct to positive!!! I also decided to test the resistance of the battery earth terminal to metalic points all round her and they are ok UNTIL i would turn the key start to fully on, ie start position.
It would seem that something is putting a drain on the current as the starter turns until the second lead supplying everthing else but the starter is connected.
Earth points do seem lacking with the main one from battery negative to Gearbox/transfer only. Any suggestions O wise ones?
I'm braving the Norn Iron (N.Ireland) weather this pm & trying to remove a fuse at a time to see what happens. At least the sparks will keep me warm!
Cheers all,
Andyroo

Just tried taking fuses out 1 by 1 and relays too & no change, she just clicks.(with positive supply and cable to alternator & rest of vehicle connected but direct positive flylead from positive to solenoid)
HELP!

dodgy relay or bad connections try a jump lead from battery earth to engine block

Ok, so you've ruled out the red wire to the starter, the starter itself, and the solenoid. Also, the battery looks ok.

If it were me, i'd still want to rule out earths. Connect the black jump lead to the battery negative terminal and to the engine block, preferably near the starter. (with both red leads connected to the battery). Try it then.

There isn't a huge amount of unfused lives in a fender, so not much that could short out and cause the symptoms you're seeing. If I really thought it was an unfused circuit shorting. I'd want to rule out the alternator, so try it without the main wire to that connected. Don't get me wrong, I don't think this is your issue. I've never known an alternator to fail in a way that would cause the symptons you're seeing, but it is a high current device that could concievably (but amazingly unlikely) fail and sink fairly high currents without you seeing smoke.

You say you did a resistance test to check the earth at various points around her, but you don't mention what exact test you were doing. Were you measuring resistance (in Ohms) or continuity? Again, don't get me wrong, I dont think this would really help diagnose the issue you have, but then you said 'they' were 'ok' until you turned the key. What do you mean by this? Did you see a change in resistance? or your continuity test went haywire?

My gut feeling is you don't have a good enough earth between your engine, chassis and the rest of the earths in the loom.

The test i did was with a multimeter from directly on battery -'ve to various points on chaisis and engine via a jump lead connected to the other meter lead. There was continuity (digital & audio from meter) until key turned to full engine start/crank position when continuity stopped.....why?? Did try disconnecting alternator leads and no change. As i say, direct +'ve to starter solenoid alone & a flylead from small terminal to positive direct will crank her but do same except other lead connected to +'ve supply that supplies elsewhere and clickity click but no cranking over!

where should i look for earth connections?

A continuity tester will trigger at very low current, typically about 10 to 30 milliamps. Its good for telling you that some current will pass, but not that high current will pass. A measurement of ohms would have been a better test.

If your engine and vehicle electics are grounded, but via a dodgy cable that now has a relatively high resistance, you will see continuity because the resistance is low enough not to bother the continuity tester (more than 30mA will still pass). But when you turn on the ignition, it will drag the your vehicle earths up to very near the voltage of your battery positive terminal (peeing off your continuity tester because you're now trying to earth your car through your meter), putting a volt drop across the dodgy earth cable. When trying to put a very high current through that same wire, you will have a significant volt drop across that wire.

As I said above, put a jump lead from negative battery to the engine block. Try it then. If it spins, replace your earth cables from your battery to your chassis and engine/gearbox.

I left my 90 for nearly 3 months a few years ago and on returning she wouldn't start, lights OK, electrics worked... I was certain it was not the starter so I took off all the earth terminals, cleaned them up with a file, cleaned up the chassis, bolts etc, and refit, put some vasilene over them to keep water from getting at them as bad. Turned the key and away she went.

It seems though that they might be fine as you did say it will spin if you do the positive supply directly, so earth should be OK, BUT rule it out first, I've seen stranger things!

Had a similar problem a few years ago and found that te earth let enough return for the starter to spin, but not enough to engage the crank.

My multimeter said that I had a good circuit, but it still didn't work!

It took me weeks to find that it was a very slightly loose connection on the earth strap.

Check and double check your earths starting at the battery and then work your way through them all.

OSD