ok drove the car to get a rwc and rego got it registered now the following day i go to start and it wont crank i only get intermittent clicking of the starter solenoid, other stuff it does is you here light relays clicking if you turn them on with or without the key on and i run a microjunk lt-12 and it will prime all good until you go to turn it over then its like the is a short and it sounds like it doesnt have enough voltage and a few relays click any ideas i have my batery in the boot motors earthed every thing is eathed only 20 ohms resistance brand new battery tried i bought it today and it cranks my xr8 so any help please

20 ohms is too high.

ok i put some more earths in and got it down to 10ohms considering <100ohms is considered ok the starter just clicks still and if you let it click say for five seconds the efi relay and pump relays buzz i tried to get it crank with fuses removed and it just clicks is their a fuse i couldnt find for the starter or is their a switching relay when cranking if so where is it help would be appreciated. but if you turn ignition on and put everything on the the relays buzz

The starter is triggered by the purple wire straight from key in manual car or by netural relay next to head light if auto , it could be a bad contant in relay or solenoid

10 Ohms, is a little more reasonable but I'd want to see under 1 Ohm for such a short run. The cable is sinking 1.2A just sitting there. The battery will go flat over a few days. test: 1. Turn the engine over with a socket on the front balancer. make sure nothing seized. 2. note the batttery voltage whilst trying to crank, or simply put the headlamps on. Do the lights turn yellow or dim completely when trying to crank. if so, battery or earthing or your 10 Ohm earth leakage is too high. Get a battery connection direct to the starter and crank engine. note the batttery voltage during cranking. A 10 Ohm earth leakage will use electrolisis to corrode the connections so best check all the earth points regularly. Vl's need a clean earth point on the engine mount where 3 harness earths must be connected at the same point (same bolt) to ensure no floating earth is produced in the circuit. If a floating earth is created, the resistive nature of this can cause the starter motor to pull current from other electronic devices that have a lower resistive path to earth in the car which will/can cause those device to melt/burn internally.

found the problem my boot earth from my fuel tank to battery there was a washer that had been arcing removed washer and was fixed cheers for the help.

good stuff, it's often such an easy fix but a b1@tch to find Some original photos have not been recovered yet.

How do you measure the earth resistance?

Quote: Originally Posted by MxPx VL How do you measure the earth resistance? Ur better off checking voltage drop across it no more than 0.3 of a volt and has to be checked under load . Example to check the voltage drop of a battery terminal put multi meter on dc volts and put connectors between battery post and battery terminal and have sum one crank it . Same deal jus move along the circuit . DO not disconect anything every thing is done in place .