Date: Sat, 2 Nov 2013 01:33:03 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Runaway Starters and Kill Switches
In-Reply-To: <527483E0.30504@gmail.com>
Content-Type: text/plain; charset="us-ascii"
Run away starters are a rare occurrence but it does happen. In the stock set
up it can be due to a bad ignition switch, the starter solenoid contacts can
weld, the starter can become mechanically hung up, or there could be a short
or cross connection in the wiring. Your starter booster relay ads another
possible failure point. I don't know what type of relay you have but the
solenoid itself is a highly inductive load. When it is turned off, there is
a huge reverse voltage spike as the magnetic field collapses. The switch
that breaks this circuit has to be designed to withstand this spike or
something is needed to absorb it. The ignition switch uses a mechanical snap
action to separate the contacts. Small 12 volt relays can micro weld and
stick closed. The proper relay for this jib will have a substantial spring
and will have double break contacts just like the solenoid does for the
starter motor.
These vehicles left the factor working with just the ignition switch and
they started fine for many years. There is no need for the relay and it is
just another failure point. Remove it and if you have an issue diagnose it
find out what is wrong. This can be frustrating. In most cases the problem
is a defective starter solenoid. Even with Bosch brand rebuilds I have had
many in a row that didn't work quite right. If you can't get 8-10 volts to
the solenoid coil you need to find out why. The relay is just a band aid for
a failing component.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
JRodgers
Sent: Saturday, November 2, 2013 12:47 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Runaway Starters and Kill Switches
OK, I am becoming very paranoid.
I have two 88 Vanagons - both of whom have had runaway starters in recent
weeks.
The first disengaged the flywheel but ran until I could get the passenger
seat moved forward, access the battery box, apply a wrench- and remove the
cable from the battery post - which all seems an interminable period of
time. It killed the starter. Had to get a new one,
The second was on the Volksiebus - the 88 Transporter a few days ago.
Fortunately as I was struggling to get the passenger seat moved forward for
access to the battery box - it shut itself off. And, to add to my
consternation - it works just fine an hasn't faulted since! But oh do I ever
know - if it's one it once - it will do it again.!!
I have start relays on both these puppies - never had a lick of trouble ever
- then this = two of the same episodes on different vehicles with in a few
weeks of each other. Totally weird! I have looked at the relays very
carefully - I don;t thinks it;s a snowballs chance in July that they are
somehow at fault.
But what would bypass the ignition switch and keep power to the starter and
keep it running - with the ignition off!!
Any ideas?
And - I's so paranoid over this I think I need a kill switch. Any ideas on
those and were to put them?
Thanks,
John
