Ballast resistor for low ohm coil

[brewsky]

I ordered a new dual-fire coil for my dream and it only reads 1.6 ohms across the primary.

If I add a 3 ohm ballast in series, that should bring the resistance back up close to the original 4.5 of the stock one?

Am I missing a potential problem using this setup?[/quote]

[garncarz]

Two issues: (1) Why would you want to purposely reduce the output voltage of the new coil? and (2) At 12 volts, your coil is drawing almost 8 amps. You would therefore need a 100W (really big) resistor. Might want to do some more research.

[brewsky]

!. You are right...I don't especially want to reduce the output of the coil....especially when starting.

2. If I add a 3 ohm resistor in series, that should drop the current to 2.6 amps....assuming the resistor doesn't increase in value as it heats up, which would bring the current down even further.

Maybe a switch to short the resistor for cold starting only?

Maybe I've done too much research!!!

http://www.randakksblog.com/ballast-res ... procedure/

[brewsky]

Ok, does anyone have the actual primary ohm spec for the OEM coil?

I can't find it in the manuals,,,,I have 2 different original ca77 coils handy, and one reads 4.5, and the other 3.6?

[Geoff Hastings]

Most set ups using a ballast resistor have it out of circuit when cranking to allow for volt drop at the battery and then have it in circuit to prevent the coil being over powered under normal running. The Honda just earths the starter solenoid via the button when cranking so you might not find it as straight forward as it seems.

[brewsky]

Just thinking out loud here....what about the ballast in series with the coil for normal running, and install a jumper from the hot terminal of the starter to the coil side of the ballast?

That should provide as much voltage as available when starter button is pushed, and cut out when released?

Edit: will not work....disregard