hi guys,

im getting a voltage drop from 12v to about 3 volts on my coil pack when cranking, i have the 12v supply fed fromthe ignition feed and it also powers the edis on the same wire, how do i stop the voltage drop?

get a new/bigger/properly charged battery?

What is the battery cranking voltage ? about 10 volts is normal, less than 9v or if it drops to 6v then rises after a couple of seconds back to 9v to indicates and dead or gassing cell.

Also check the earths to battery are clean and good --- engine, chassis and ignition unit.


[Edited on 21/7/08 by britishtrident]

Yup. Check the battery voltage when cranking. Very much doubt it'll drop as far as 3v though because if so the starter motor would hardly go round..

Fun fun fun!! Somethings pulling more amps than it should or causing a whole load of resistance!! Time to get out the DVM again when cranking and see what voltages you've got at various places in the loom....

Might be worth stick a voltmeter between the battery negative and the cylinder block when cranking --- this is away of testing for a bad earth connection.