Date: Sun, 10 Aug 2008 10:13:56 -0700
Reply-To: neil N <musomuso@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: neil N <musomuso@GMAIL.COM>
Subject: Re: Bentley wiring typo?
In-Reply-To: <B6E25CA77DA147E186466A8E78AA90E7@DADSTOSHIBA>
Content-Type: text/plain; charset=ISO-8859-1
Ah.
A heftier relay, drawing more current, would open when ign. off
because the small amount of "feed back" power isn't sufficient to keep
it closed. And as you mention, having a heavier spring too wouldn't
hurt in that regard.
Well I do have one of those "can" type solenoids kickin' around!
(no I won't be installing it --- ;^)
I get it.
Re: installing the relay. I hear ya.
As Mark advised, checking to see what the Jetta coil actually draws
would be a good idea. I should have done that before deploying the
installation of yet another potential failing point. The relay is
likely not really needed though I have read that the Jetta coil
produces a pretty hot spark. Regardless, there will be more room in
the relay box without it.
I'll bust out my VOM and learn how to measure current draw. (quite
easy I'm sure). If a new wire is needed, I'll deal with it.
Lesson learned
I like simple.
In the big picture this isn't even a minor inconvenience. But it bugs me.
Next glitch: fuel gauge (new sender. still not right!)
Thanks Dennis
Neil.
On Sat, Aug 9, 2008 at 9:25 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> The problem is your relay is not drawing enough current for the original
> circuit to work properly. Only a small current is needed to keep that
> relay energized once it is pulled closed.
>
> A better relay with a larger coil and real spring may be better suited for
> this application. I can't imagine the Jetta ignition coil needing so much
> more current that the ignition switch can't handle it anyway. This may be
> one of those times where fixing a problem that didn't exist caused more
> harm than good. Adding a relay here also added another point of failure
> and a relay welding closed can be as much of a problem as an ignition
> switch failing.
>
> Dennis
>
> -----Original Message-----
> From: neil N [mailto:musomuso@gmail.com]
> Sent: Saturday, August 09, 2008 11:53 PM
> To: Dennis Haynes
> Cc: vanagon@gerry.vanagon.com
> Subject: Re: Bentley wiring typo?
>
> Thanks Dennis.
>
> I thought I'd reinstall the fridge relay to solve the "handbrake on,
> engine off" problem. Didn't help.
>
> Related to all of this, I think the culprit to the "handbrake on,
> engine off" scenario has been found.
>
> Because the stock Vanagon wire from 15 of ign. switch to the coil, is
> a smaller gauge than what is used by the Jetta coil ( I installed a
> 2.0 Jetta engine), I installed a relay, that is (obviously) triggered
> by the stock ignition wire, to carry power from 30 to this larger wire
> that goes to the Jetta coil.
>
> Something I failed to mention in my original post regarding this odd
> problem. My bad.
>
> This evening, I recreated the scenario where the engine would stop,
> only with key "off" and handbrake on. When this happened, I left the
> handbrake off (down) and pulled the blue wire from the alternator.
>
> Engine stopped.
>
> If I understood everything correctly, as per Mark Drillocks
> suggestions, I'm pretty sure there is a "feedback" of power from the
> alternator to the "coil" relay I installed. Obviously this keeps the
> relay switch closed even if key turned "off".
>
> Odd thing. After engine has been driven a while, this won't happen.
> The ignition switch works as it should. Only seems to happen with a
> cold engine driven ~ 4 minutes.
>
> Funny.
>
> Either I'll install a diode on the blue alt wire, run a new larger
> gauge wire, or see how much current is drawn by the Jetta ignition
> coil and determine if the Vanagon wire can handle the load. (Thanks
> Mark!)
>
> Thanks again,
>
> Neil.
>
>
>
|