Date: Tue, 26 Jan 2016 16:22:11 -0500
Reply-To: Larry Alofs <lalofs@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Larry Alofs <lalofs@GMAIL.COM>
Subject: Re: Starter relay with automatic and cruise, was: Starter woes
In-Reply-To: <56A7C79A.4000102@cox.net>
Content-Type: text/plain; charset=UTF-8
Thanks Mark,
I hadn't thought of it from that point of view. I had just assumed that
the relay coil would not supply a good enough ground for the cruise to
work. Now I see that the problem is a more serious one. I should be able
to take the relevant measurements on my van. I also believe that I have
one of those "Ford fender" type of solenoid relays, for starters that used
a Bendix. :-)
Larry
On Tue, Jan 26, 2016 at 2:23 PM, vw_van_fan_Mark <madvws@cox.net> wrote:
> 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
>>>
>>>
>>>
>>>
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