INstal new oms pump

[Reg Sch]

Hi Guys,
Can anyone help?
I purchased a new OMS pump (4wire unit) to replace an older VRo( 3wire unit) from Boats . Net for my 1989 110 hp Evinrude.
The installation instructions were clear,however when installed and running the engine with an oil/fuel mix and oil line disconnected the " no oil" warning alarm was not activated.
The alarm chirps when the ignition is turned on, and functions when the over heating wire is shorted to earth, so I believe the alarm is ok.
The Installation instructions cover changing the wiring to use the 4 wire unit however is it intended to actuate the alarm on a 1989 model?
Any ***istance greatly appreciated
Reg Sch

[boats.net]

The alarm should activate if there is no oil in pump, if you primed oil system before testing alarm then would not get an alarm.

[Reg Sch]

REplaced OMS pump

HI,
The unit was installed ,as supplied, ie, no oil was ever connected.
The Motor was run for several minutes but the " no oil " alarm did not activate.
REg Sch