Date: Thu, 15 Nov 2007 19:39:55 -0800
Reply-To: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel - Shazam <scottdaniel@TURBOVANS.COM>
Subject: Re: Fuel pump relay cutout switch
In-Reply-To: <473CD551.9060202@cox.net>
Content-Type: text/plain; charset="us-ascii"
Yes, great layout - one small problem, were the wire to short to ground so
it would always revert to 'will run safe mode' ...if the wire ever did
short, the operator of the van would have a false sense of security since
the switch he/she was turning off and on wouldn't really be doing anything.
Personally, were I to want to employ this strategy as anti-theft
....disabling the fuel pump relay or fuel pump, I'd put a switch in the wire
between the ecu and the fuel pump relay...the wire that supplies ground to
the relay to energize it. Barely any current in that wire, so not a bad
signal to go messin' with, and you could use a really tiny switch.
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Mark Drillock
Sent: Thursday, November 15, 2007 3:25 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Fuel pump relay cutout switch
The 3 wire options mentioned are all at the VW ECU wiring relay box
which he may no longer have or which may have been modified. Of course
he could do something under the van close to the pump like you point
out. It all depends on how tricky you want it to be for someone to
bypass the anti-theft system. Much easier to bypass one detectable
outside under the van. Not so easy to bypass in the engine compartment.
I would interrupt the fuel pump main ground wire with a relay contact
added to the compartment in a visible location, controlled by a single
wire run to a switch up by the driver. The single wire would in turn
provide a switched ground for the relay coil.
Running a single wire that provides only relay ground is safe since if
it were to get rubbed through and short to the chassis the effect would
only be to always allow the engine to run.
Mark
Jake de Villiers wrote:
> Good point Mark, but the suggested approaches still apply. You could put a
> switch in the fuel pump feed that's under the van and kill it that way.
>
> On Nov 15, 2007 2:28 PM, Mark Drillock <mdrillock@cox.net> wrote:
>
>
>>I guess few noticed that he said he has a SUBARU conversion. Without
>>specific info about the wiring modifications that were made in HIS
>>conversion it may not help to suggest approaches that presume VW ECU and
>>VW support wiring.
>>
>>Mark
>>
>>Scott Daniel - Shazam wrote:
>>
>>
>>>Thanks for saying what you are trying to accomplish.
>>>Your idea is sound, and you could interrupt any of 3 wires at the fuel
>>
>>pump
>>
>>>relay,
>>> - the 'supplies ground' signal from the ECU.
>>> -the power supply wire to the relay,
>>> - or the 'hot signal coming out' wire that goes to the fuel pump.
>>>I'd access the fp relay in that black box above the coil, figure out
>>
>>which
>>
>>>is the main relay and which is the fuel pump relay and proceed
>>
>>carefully.
>>
>>>It really is clearly indicated in the Bentley current flow diagrams, tho
>>>they are funny to read at first for sure, but if you find the current
>>
>>track
>>
>>>for 'fuel pump' .....you should be able to see the pump, and the relay,
>>
>>even
>>
>>>how it works internally, if you understand the basic principle of a
>>
>>relay
>>
>>>anyway. . They don't always show things really well, but on these basic
>>>circuits, they're ok.
>>>Scott
>>>www.turbovans.com
>>>
>>>
>>>-----Original Message-----
>>>From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
>>
>>Of
>>
>>>David O'Bryan
>>>Sent: Wednesday, November 14, 2007 3:01 PM
>>>To: vanagon@GERRY.VANAGON.COM
>>>Subject: Fuel pump relay cutout switch
>>>
>>>Help. I'm helpless when it comes to reading a current diagram (but I
>>
>>really
>>
>>>did try). I want to install a cut out switch on the wiring to the fuel
>>
>>pump
>>
>>>relay and cannot figure out which wire from the ignition switch area
>>
>>will do
>>
>>>that. I want to run the lower power wire that energizes the relay thru
>>
>>a
>>
>>>switch as an anti-theft device.
>>>
>>>Any help is appreciated. :-)
>>>
>>>Regards,
>>>
>>>Dave O
>>>'87 Westy
>>>
>>
>
>
>
> --
> Jake
> 1984 Vanagon GL
> 1986 Westy Weekender "Dixie"
> www.crescentbeachguitar.com
> http://subyjake.googlepages.com/
>
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