Possible Earth Problems

[wardy18 33 1 Cars]

The hillclimb car recently died on the line at my last event (1/4 mile sprint), got it down to electrical which thinking as its carbs shouldnt be too difficult but a ever has proved to be rather confusing

 

Tried fitting a new Ign Amp at the event but nothing worked so towed it home

 

The following morning i fitted a brand new coil and it fired up straight away, fitted the old one back to double check and again fired straight away!! DAMN IT

 

SO im thinking its either a dodgy old coil or earthing problems, i have re-fitted the new coil and will leave it place but i am very confused over the Earths

 

Earth to the ignition amp is perfect but then the earth from the amp to the coil isnt reading down to zero on my tester, is this correct?!?

 

The only other earths i have on the coil is to the rev counter and the rev limiter?!?

 

Should the coil have its own Independant Earth and should that earth from the Ign Amp not read Zero like a direct earth would?!

 

Any advice would be greatly appreciated

 

Best Regards

 

Simon

[phat205 0]

IIRC the ignition amp is earthed through is casings and the coil has an earth which runs back to the fuse box and Tacho. I had similar problems recently and ran independant earth from both to the body just to make sure.

 

Seems to have cured the problem on mine

[ade 4wd 11]

The + terminal on the ignition coil is a switched live, it should allways be +12V with the ignition switched on.

The - terminal on the ignition coil connects to the tacho and the ignition amplifier, it should not be connected to earth.

The body of the ignition coil should be earthed through its mounting bracket.

 

Check the connection between the ignition amplifier and the distributer, there is a connecter that gets corroded. A common fault.

 

Hope that helps.