T&T: Adjusting Engine Stop Solenoid Perkins 6.3544 (NA)

[KevinR]

> -----Original Message-----
> If you don't like this behavior, you need to add a relay lockout
> circuit that will not allow power to be restored to the solenoid when the
> "Stop" bush button is released.  

I would suggest NOT putting in this type of circuit unless you also put in a
release button in the same location. Otherwise, you could end up with an
engine suddenly stopping when you didn't want it to, with no way to quickly
restart.

Your problem may well be a bit different than you suspect. On many of the
old Perkins, the stop solenoid is a normally off solenoid letting the engine
run when there is no voltage on the solenoid (not the type that only lets
the engine run when there is continuous power to the solenoid). These
sometimes suffered from low voltage due to voltage loss in the small gauge
wire from the stop switch to the solenoid, resulting in only a partial
activation of the stop solenoid. This may be the problem you are dealing
with.

Many of these old Perkins (mine included) have been modified to add a relay
at the solenoid, much like the headlight relay on a car. The stop switch on
the bridge causes the relay to close, and that switches a high current large
gauge power wire to be connected to the stop solenoid. Full battery voltage
to the solenoid = full travel of the solenoid and positive engine shutdown.

Kevin