Strange alarm sounding I can't figure out

[alexh86]

2000 Johnson 40hp has been running pretty good until recently. Although I haven't timed it, the alarm seems to go off at the same exact time, every time-about a 90sec after start up. The alarm sound is is about a second long, with a very short period off. maybe a 1/4 sec. I am unsure what this alarm is. Everything i have checked doesn't seem to match up to the 4 different tone/sequence sounds . The closest one I figured was overheat, so I disconnected the wire that runs into the head tan/blue stripe and still the alarm sounds. The water pumps out warm water just fine. I premix so there are no VRO alarms. The fuel flow issues didn't seems to be an issue because the alarm sounded after I was up on plane. The fuel bulb was not sucked flat either.

The alarm will not stop until you turn off the engine.
Disconnecting either purple or tan at the buzzer will turn the alarm off.


One thing I know I need to check is the wire connections at the buzzer. I have read if the purple and tan are reversed it can give a strange alarm sound.

As far as the motor goes, it seems to idle and turn on just as it always has. I have not tried to run the motor anymore than idle until I figure out what the problem is.
Thanks!
-alex.

 

[jonesg]

Re: Strange alarm sounding I can't figure out

The VRO oil tank sensor is disconnected and wires taped off right?
what about the vacuum switch sensor at the fuel pump.?
Is the oil line capped off and sealed air tight?

 

[Joe Reeves]

Re: Strange alarm sounding I can't figure out

As "Jones" above suspects, that sound like you didn't disconnect the wiring plug that leads from the VRO pump.

(VRO Horn Warnings)
(J. Reeves)

NOTE: I retired around 1991/92. Possibly some of the later V4 engines and others may also incorporate a fuel vacuum switch that would enable a fuel restriction warning to sound as mentioned below, an unknown factor to myself.

1 - A steady constant beep = Overheating - The V/6 engines, possibly some others, have a fuel restriction warning which is also a steady constant beep.

2 - A beep every 20 or 40 seconds = oil level has dropped to 1/4 tank. (Late model engine = Every 40 seconds)

3 - A beep every other second = VRO failure, air leak in oil line, oil restriction, (anything that would result in a lack of oil being supplied to the engine).

NOTE - If the warning horn is the black plastic (overpriced) three wire type horn, the warning horn should beep once when the ignition key is turned to the ON position. If it does not, it is either faulty or someone has disconnected it (a stupid move!). At any rate, if it does not beep which indicates that the horn is non functional, find out why and do not run the engine until the problem is corrected.

(VRO Pump Conversion To Straight Fuel Pump)
(J. Reeves)

You can convert the VRO pump into a straight fuel pump, eliminating the oil tank and VRO pump warning system, but retain the overheat warning setup (and fuel restriction warning if so equipped) by doing the following:

1 - Cut and plug the oil line at the engine so that the oil side of the VRO pump will not draw air into its system. Trace the wires from the back of the VRO to its rubber plug (electrical plug) and disconnect it.

2 - Trace the two wires from the oil tank to the engine, disconnect those two wires, then remove them and the oil tank.

3 - Mix the 50/1 oil in the proper amount with whatever quantity fuel you have. Disconnect the fuel line at the engine. Pump the fuel primer bulb until fuel exits that hose with the tint of whatever oil you used. Reconnect the fuel hose.

That's it. If you want to test the heat warning system to ease your mind, have the key in the on position, then ground out the tan heat sensor wire that you'll find protruding from the cylinder head. The warning horn should sound off.

 

[alexh86]

Re: Strange alarm sounding I can't figure out

Last night I grounded the tan wire coming from the head and the alarm did not sound. I went ahead and bought an overpriced horn, hoping it's just a faulty horn. I will double check all connections involving VRO system and make sure they are all disconnected/sealed properly. Thanks for the help so far. Ill follow up once the new horn gets here.