[Healeys] Fuel Pump CORRECTION

[Bob Spidell]

This: "This would be indicated by a dead short between the input post and the ground post with the points open. "

Should read: "This would be indicated by a dead short between the points base and the ground post with the points open. "

Bob



On 12/30/2012 7:38 AM, Bob Spidell wrote:
> The pump circuit is fairly simple: it's a solenoid (electromagnet, essentially) in series with a switch (the points).  
> The power source connects to one solenoid lead at the long brass screw, which should be otherwise isolated.  The other 
> solenoid lead connects to the base of the points, where the points 'blade' is attached.  The unshielded copper lead 
> from the points connects under the pedestal hold-down screw opposite the side with the input brass screw.  The transil 
> should connect between the points base and the same pedestal screw the wire from the points connect to.
>
> When the points are closed the whole circuit will have near-zero impedance for a split second then impedance will 
> build as the solenoid coil gets saturated.  With the points open, there should be continuity between the input post 
> and the points base only (there should always be continuity from the points on the armature to ground).
>
> There is some polarity issue with the solenoid leads, but it will operate with the leads reversed.  If your pump 
> hasn't previously been assaulted the small terminals fit properly only one way (sometimes, the leads are red/black, 
> but I've only seen black/black).
>
> Did you get a bidirectional transil (like the kit I recommended)? If so, the orientation of the transil doesn't 
> matter.  If not, you could have the transil connected backwards.  This would be indicated by a dead short between the 
> input post and the ground post with the points open.
>
> Bob
>
>


-- 
*******************************************************************
Bob Spidell           San Jose, CA            bspidell at comcast.net

*******************************************************************