[Healeys] Another con - fused question

BJ8 Healeys sbyers at ec.rr.com
Thu Jan 3 07:53:51 MST 2013

What raised this discussion in the first place was fusing the overdrive
circuit.  The O/D solenoid has a pull-in coil that draws high current and a
holding coil that draws less current.  The solenoids can fail in such a way
that the internal switch from the pull-in coil to the holding coil does not
work, leaving the pull-in coil continuously activated and drawing high
current.  The concern is that the high current can damage the wiring to the
O/D.  I had such a failure once that burned up the solenoid but it did not
damage the wiring, fortunately.  But the possibility that it could have
convinced me to put a fuse in the circuit.  The ultimate purpose of a fuse
is to protect the wiring, because it's much easier to replaced a failed
component than melted wire in the harness.

You can put a fuse in the white wire, but the white wire is a heavier gauge
than the wire to the O/D solenoid.  I preferred to put the fuse in the
white/green wire to the gearshift switch and solenoid so that the smaller
gauge wire is protected.  Plus, if the fuse blows, I can be pretty sure the
problem is either in the O/D wire or the solenoid.  A blown fuse in the
white wire leaves several other possibilities to have to investigate (relay,
throttle switch, dash switch and wiring to them).'

Steve Byers
BJ8 Registry
Havelock, NC  USA

-----Original Message-----
From: healeys-bounces at autox.team.net [mailto:healeys-bounces at autox.team.net]
On Behalf Of Alan Seigrist
Sent: Wednesday, January 02, 2013 7:05 PM
To: gregwilkinson at roadrunner.com
Cc: Healey List
Subject: Re: [Healeys] Another con - fused question

Greg is correct here.  On any white wire on any british car (including all
austin healeys), it is switched power, unfused.

You can put a fuse on the white wire between the junction and the solenoid.


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