Date:         Fri, 25 Jan 2013 18:59:06 -0800
Reply-To:     neil n <musomuso@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         neil n <musomuso@GMAIL.COM>
Subject:      Re: Ignition Switch "Su" Power
Comments: To: Larry Alofs <lalofs@gmail.com>
In-Reply-To:  <CA+r=JhqRUkWDko1cwMJsa_5UGv0j4JK=oku=r_wz85=j8C=spg@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Hi Larry.

Maybe my statement below was misleading. The Mk3 Jetta ECU is wired to
the correct OEM Mk3 power relay. Image of relay:

https://sites.google.com/site/tubaneil2/PowerRelayDiagram.jpg

I could be wrong, but for OBD1 Motronic, when key turned to ign. on,
15 is connected to pin 38 of ECU. The ECU then supplies ground to the
power relay. This relay then supplies + to various components. (fuel
injectors etc.)

The Jetta OEM wire from 15 supplies  +  to the coil and the ECU.


Neil.

On Fri, Jan 25, 2013 at 4:17 PM, Larry Alofs <lalofs@gmail.com> wrote:

> I would be very hesitant to use the coil wire to also supply the ECU.  The
> coil is an inductive load which is switched on and off.  This tends to
> generate voltage spikes which are  harmful or at least annoying to sensitive
> electronics on the same circuit.
>
> Larry A.
>
>
> On Fri, Jan 25, 2013 at 4:13 PM, neil n <musomuso@gmail.com> wrote:


>> Thought: use Vanagon coil wire for  +  to ECU and relay for  +  to the
>> Jetta coil
>>
>> mocked up diagram:
>>
>>
>> https://lh5.googleusercontent.com/-qjVqWgmKgiA/UQLzz0KnCHI/AAAAAAAAGq8/dV79PgDqWQg/s720/ABA%2520swap%2520coil%2520wire%253F.jpg



--
Neil n

65 kb image Myford Ready For Assembly  http://tinyurl.com/64sx4rp

'88 Slate Blue Westy to be named.

'81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/

Vanagon VAG Gas I4/VR Swap Google Group:

http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines