[Healeys] *** SPAM ***Re: Timing light query

[sentenac.rw at gmail.com]

Polarity also matters in a different way if your timing light has a
metal case  and one of the power leads is grounded to the case, as
mine is.  If you use a 'regular' timing light designed for negative
grounds in a Healey with a positive ground system, and if you then
touch the case to the chassis or engine you will get a lot of sparks
at a minimum, and maybe do some welding where you had not intended to.

-Roland
BN1 #724

On Mon, 11 Mar 2019 21:32:53 -0400, Michael Oritt wrote:

>Simon--
>
>The 12VDC lead does not need to go to the battery, merely a source of power
>whether or not it is part of your car's electrical system.  I don't know
>how your engine is configured but you can take power off of the starter
>solenoid, coil hot lead, etc. etc.  Polarity does matter, however.
>
>Best--Michael Oritt
>