Date: Tue, 23 Dec 2014 11:57:10 -0600
Reply-To: John Rodgers <jrodgers113@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: John Rodgers <jrodgers113@GMAIL.COM>
Subject: Re: Trying to understand starter stuff
In-Reply-To: <02fb01d01ed0$7c467ed0$74d37c70$@gmail.com>
Content-Type: text/plain; charset=UTF-8
I have one of Jay Browns starter relays on both of my vans. Recently I
discovered that I could pull the relay cover and actuate the relay by hand,
thus making it work as a remote start switch when working onthe engine.
Very handy.
John
On Dec 23, 2014 10:49 AM, "Stuart MacMillan" <stuartmacm@gmail.com> wrote:
> Here is a nice relay setup:
> http://www.thesamba.com/vw/classifieds/detail.php?id=1119534 (Won't work
> with an automatic with factory cruise control for some reason though.)
>
> Stuart
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
> David Beierl
> Sent: Monday, December 22, 2014 9:46 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Re: Trying to understand starter stuff
>
> At 11:03 PM 12/22/2014, Marc Perdue wrote:
> >Hi all,
>
> Excellent! I now have three verified cases of a starter control lead
> coming
> off without causing a hard start failure: your Van, my '89 2.1l, and my
> '71
> Fiat 128. I solved that one after running out of gas in an uphill line to
> buy gas somwehere in upstate New York, when it became clear that the motor
> would crank if it were torqued slightly sideways.
>
> Starters have some challenging necessities. They have to have big cables
> direct to the battery; a heavy switch that can switch them on and off under
> load without burning up quickly; a means of engaging the pinion into the
> flywheel ring gear; and a positive means of disengaging it when the motor
> starts, so the starter doesn't burst from overspeed.
>
> Back when the world was new the electrical switching was done by a
> heavy-duty relay that would today be called a contactor but was commonly
> known as a solenoid. It was mounted somewhere between battery and starter,
> and a light wire from the starter button or key switch used to activate it.
> For testing you could use a screwdriver to jumper between the big battery
> cable connection and the control terminal. Starter "solenoids" were a
> commonly available FLAPS part and no doubt still are; as they regularly
> failed in use. Last one I bought cost three or four dollars. Excellent
> for
> switching a couple hundred amps DC but not rated for continuous duty.
> They're meant for starting cars, once per trip segment, plenty of time to
> cool in between.
>
> Engaging and disengaging the pinion was accomplished by a clever invention
> called a Bendix drive. The pinion was mounted on the starter shaft and
> engaged a pair of helical slots in the shaft. It was kept wound down to
> the
> bottoms of the slots by a light spring that pressed it away from the end of
> the shaft. When you hit the button, the shaft would spin violently and
> hurl
> the pinion into engagement during the first few revolutions. And when the
> motor started, the ring gear would spin the pinion back down the track out
> of engagement. It worked a treat, so long as you kept it clean and not
> gucked up with oik or grease. The Bendix Corporation waxed fat and happy.
>
> Came the day that someone thought it would be better to combine actions.
> If
> the contactor were mounted on the starter it would simplify wiring, and it
> could be used as a real solenoid, to physically throw the pinion into
> engagement as well. Or rather a solenoid could be thus used, and with some
> contacts added could perform the contactor function as well. An
> overrunning
> clutch would handle decoupling the starter from the engine, leaving the
> pinion in engagement but not forcing the starter to keep up with it. Full
> disengagement would happen when the key was released. Over a decade or two
> this method largely took over for starting cars, and that's how Bosch did
> it
> on our starters.
>
> The big cable goes direct from battery to starter, where it meets the
> thinner wire from the alternator that supplies charge. That connection is
> subject to corrosion. The ground connection through the starter, bell
> housing, transmission ground strap may be defective. The solenoid itself
> wears and gets crudded up; you have to take the starter apart to clean it
> up. Non-A/T versions of this starter have no bearing at the pinion end;
> the
> shaft inserts into a sleeve bearing that's in turn inserted into the bell
> housing of the engine. That wears and needs renewal. And the solenoid
> gets
> its operating power not from that fat cable but from battery to panel to
> ignition switch and back to the starter. It only needs two or three amps,
> but it's a long trip. It's easy to see if a relay could help it -- just
> jumper the alternator B+ post to the starter control terminal. You can
> reach it by reaching your hand over the top of the bell housing, quite a
> way
> forward and then to the right. There's probably a spare terminal to latch
> on to. If it cranks snappily that way and listlessly by the key, add a
> relay. If it makes no difference, neither will the relay.
>
> Yours,
> David
>
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