Getting over my overdrive ...

[DOUG MILLER]

Hi Byron,
I have had intermittent disengagements and unpredictable failures to engage 
for over a year with my BN 2.  Every time I tried to diagnose the problem 
the solenoid would perform as it should.  However the last time I had the 
tunnel off and went through the drill several times, the solenoid finally 
failed to actuate.  I put my hand on the solenoid housing and it was very 
warm.  A few minutes later it cooled down and worked again.  I am assuming I 
have had an intermittent internal short inside the solenoid.  I put on a new 
solenoid (from Moss) before going to the Rendezvous.  It worked every time.

You should put an ammeter in the circuit to ensure that the steady state 
current is dropping from the pull-in current of about 12 amps to the hold-in 
current of 1 to 2 amps.  The pull-in current will burn out the solenoid if 
the limit switch inside the solenoid fails to work or engage.

The lack of a rubber bumper or other stop mechanism can allow the solenoid 
plunger to drop below the level where the magnetic field will pull the 
plunger into position.  I assume when this happens the solenoid will 
continue to pull 12 amps while the overdrive switch is closed.  I made my 
own bumper from a rubber insert similar to those at the bottom trunk lid 
lip.  Some guys tap the stop land on the housing a use a small screw that 
gives them the ability to adjust the level of the stop.

I hope this helps.  If this isn't clear email back or call me on (360) 
638-1324.  I am still having a problem with the O/D dropping out 
(unpredictably) at near full throttle, especially when the engine 
compartment is hot-as it was on the way back from K Falls.  I am going to 
replace the throttle switch.  Both the throttle switch and the solenoid are 
probably original equipment on the car so it is not surprising they have 
developed problems.

Good luck,
Doug