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					Originally Posted by  infernosg
					 
				 
				The only specs I can find on the coils say 19 A max but I think that's for the internal ignitor to the coil and not the external power draw.  I've read a single 20 or 25 A fuse is suitable for four coils.  The 18 AWG sections are short - 12 in. at most.  The 16 AWG portion is the longest being something like 6 ft. 
			
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 Four of the IGN-1As will draw around 5 amps at idle with a charge time of 4.5ms in direct-fire mode.  As the revs go up and duty cycle increases, the amp draw will go up a bit to around 8-10 amps.  This is on a 12V system.  I've had one guy use these on a 16V total loss system and he had to build the circuit to support 30A max to run 4.5ms charge time.  He's also getting a good bit more mJ out of the coil at that voltage and charge time than one would with a 12V system.
I build our harnesses with a 14G feed for primary + and - that's spliced down to 18G 10-12" from the coil.  This is using M22759/16 wire.  If I were using standard auto hookup wire, I'd probably go up one size.