The solenoid operation is very simple. When it is energized, the valve is
open, permitting flow either way through it. The valve is connected between
the pressurized lines and window raising cylinder. The pressure is present
in the lines only when the pump is operating, and the pump is operating only
when the operator is trying to put a window up.
When the operator is trying to put the window down, the pump is not running,
but the same solenoid is operated, allowing the spring and gravity to push
the window down, exhausting the fluid back into the pressurized lines, from
whence it returns to the sump.
The system therefore has a few strange tricks. For instance, if you are
trying to lower one window while raising another, or while adjusting the
power seat, or while operating the convertible top mechanism (if equipped),
both windows go up.
Similarly, if you are trying to lower two windows at once, and the spring
forces are not equalized between the two windows, the one with the stronger
spring will go down, and the other will go up, until the first window
bottoms out.
This also means that the control switches are quite odd. While they look
like normal power window switches, they operate as follows: "center" is
off, "up" puts 6 volts on both output contacts, "down" puts 6 volts on only
one contact.
If these switches get mixed up with those from an electric window car,
strange things result!
Dick Benjamin (who owns a car with all these features, plus a power antenna
too!)
----- Original Message -----
From: <gimpineer@xxxxxxxx>
To: <mailing-list@xxxxxxxxxxxxxxxx>
Sent: Tuesday, June 25, 2002 3:09 PM
Subject: Re: IML: Fw: solenoid 6V More, More, More ?
>
> On Tue, 25 Jun 2002 10:51:51 -0700 "Dick Benjamin" <DickB@xxxxxxxxx>
> writes:
> > The pressure in the system is about 250 PSI (assuming this is the
> > same pump
> > as used by Packard). Remember that the solenoid valve has to
> > resist
> > pressure in either direction - this may not be what the ones you are
> > looking
> > at are designed to do,
>
> A few thoughts about solenoids.
> How is the hydraulic circuit arranged? Are there two solenoids, one to
> open (feed) and one to close (bleed)? If not, how is the pressure
> relieved to close window? Is it a multi function solenoid? Is there a
> supply line only or a supply and return line? Does the pump run
> continuously, cycle to maintain pressure or cycle with the window piston?
>
> If the valve is not just the right capacity (Cv) it could work too slowly
> or slam open and closed. If you don't know the exact size, I would
> suggest that you go a little large and pipe an adjustable flow control
> valve in series. This is just an adjustable (and inexpensive)
> restrictor. It can be adjusted for smooth operation. It should be
> available from the same vendor as the solenoid.
>
> Inquiring mind wants to know.
>
> 4 - Toes
>
>
Back to the Home of the Forward Look Network