[Top] [All Lists]

Re: Coil Question

To: "Neil Cotty" <>, <>
Subject: Re: Coil Question
From: "Paul Hunt" <>
Date: Fri, 20 Aug 1999 19:28:55 +0100
A coil is either a 12v coil or a 6v coil.  If it is 6v coil used on a 12v
system then an external ballast - usually a length of resistance wire
contained within the loom - is required.  Whether a coil has an internal
ballast or not is completely immaterial, it is the coil spec that is
important.  The MGB coils were 12v (HA12) with a resistance of about 3.2
ohms up until 1974-ish (in the UK, at least).  Thereafter the 6v coil was
used ( 16C6) with a resistance of about 1.5 ohms.  The ballast wire starts
off as a white at the fuse block/ignition relay end and becomes a
white/green at the coil, extended on to a special contact on the solenoid
which delivers 12v during cranking.

Haynes refers to the 6v coil as "16C6 (6 volt with ballast resistor)" and
this *definitely* refers to the external ballast, not any internal ballast
that might or might not be present.

Forget the issue of internal ballast, an MGA requires a 12v coil.

(or if that URL doesn't work try   )

-----Original Message-----
From: Neil Cotty <>
To: <>
Date: 17 August 1999 05:20
Subject: Coil Question

>Hi all,
>Getting my new Bosch dist. tomorrow so I decided to replace the one I took
>from my MGB which is 29yrs old with a Sport coil type. Bosch have just
>re-released their GT40 in the round style so I won't have to go drillin'
>holes in the A to fit their new funky shaped one.
>The Bosch catalog says the MGA requires a coil WITH a ballast resistor.
>Surely this isn't right. The one I took off my A was a Lucas HA12, and the
>one off the MGB (70) didn't use a Ballast resistor either. Can someone just
>clarify that for me that I need one WITHOUT a ballast resistor. I'm 99%
>I'm right, just don't want to order till I'm 100%..! <G> :)

<Prev in Thread] Current Thread [Next in Thread>