Date: Tue, 26 Jan 2016 11:23:06 -0800
Reply-To: vw_van_fan_Mark <madvws@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: vw_van_fan_Mark <madvws@COX.NET>
Subject: Starter relay with automatic and cruise, was: Starter woes
In-Reply-To: <CA+r=JhphL190he0oYSEi75q-Ri=L4ydLtoJFseh0kjnz4u49Xw@mail.gmail.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Larry, I wouldn't modify the cruise control circuit. I'd approach the
problem from a different direction.
For those not aware of this situation, the problem is that when a
certain combination of options is installed the added starter relay can
be triggered to run the starter even when the engine is already running.
This is a bad thing.
The basic issue is that the commonly used small starter relays are very
easily triggered. While they are sold as 12v relays they will activate
at much lower voltage than that and only need a very small current as
well. The stock cruise auto trans relay is feeding a weak voltage and
small current into the starter switch wiring under certain conditions.
This falsely triggers the added starter relay. If you use a more
substantial starter relay device, like a starter solenoid relay, that
small voltage and current won't be enough to falsely trigger it. That is
my theory anyway.
I don't have a van available to fool with that has the right combination
for testing this idea or I would do so.
Likewise I think you could come up with a simple electronic fix to the
small relay kit itself to prevent it from being triggered by the cruise
auto trans relay but again I don't have a test subject.
Mark
Larry Alofs wrote:
> Mark,
> I have added relays successfully to a number of vanagons in the past. My
> current driver is the first that I have had with AT and factory cruise.
> Since I would like to add a relay, I have read your past posts on this
> topic with great interest. After spending quite a bit of quality time with
> the diagrams in the Bentley I have concluded that the cruise system gets a
> ground signal thru the starter trigger wire and that if this is eliminated
> the cruise doesn't operate. The only reason that I can see for it to be
> designed this way is so that the cruise will disengage if someone
> accidentally bumps the shift lever into neutral while underway.
>
> Does this make sense to you?
>
> Could a relay be installed safely if this function could be duplicated some
> way?
>
> Thanks,
> Larry A.
>
>
> On Tue, Jan 26, 2016 at 9:02 AM, vw_van_fan_Mark <madvws@cox.net> wrote:
>
>> It is the auto tranny vans with cruise that have the known conflict with
>> the added starter relay. The cruise system is more complicated on
>> automatics and is tied into the starter switch wiring. This isn't the
>> case with manual trans vans with cruise.
>>
>> Mark
>>
>>
>>