Date:         Thu, 29 Jan 2009 09:54:07 -0600
Reply-To:     Larry Alofs <lalofs@GMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Larry Alofs <lalofs@GMAIL.COM>
Subject:      starter solenoid current remeasured
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A couple of weeks ago I stated that I had measured the starter solenoid
current and got a rather surprising result of 37 A.  One of the
knowledgeable pros on the list replied that he thought my meter had been
fooled by a spike and that the current was around 8 A.

Yesterday I repeated the measurement using a different digital meter and
also a primitive analog meter of the type that you used to see on tractors,
etc.  I checked two starters, both AT, one from a 1.9 and the other from a
2.1, a Bosch reman. with a new solenoid.

Both meters and both starters gave a current measurement close to 25 A.  It
didn't matter whether I used the body of the starter for the negative
connection or the little strap between the solenoid and the starter.  With
the digital meter I could see the current decrease an amp or so as my clip
leads rapidly heated up.

This is a lot of current for the contacts in the ignition switch.  You also
get arcing when you disconnect form an inductive load like this.

Anyone installing a relay should use one rated at 30 A or more.  As I
recall, when I removed the harness from my subie donor I found that it used
a relay to operate the solenoid.

Larry A.
always looking for empirical data