1990 V6 constant alarm immediately at startup

[d.boat]

Hi: Just started my 1990 200 HP V6 for the first time this season. The engine has a functioning VRO/OMS system, updated the fuel pump and tank about three years ago and haven't had any problems at all. This system has alarm patterns - constant for fuel restriction and overheat, rapid intermittent for no oil, slow intermittent for low oil.

I get a constant alarm immediately upon startup. I mean immediately - no time for the engine to warm up. The alarm sounds constantly with the key in the "run" (not start") position.

I am only running it at high idle (on the hose) and the fuel bulb is hard. I've even tried pumping the hard bulb and also have tried pushing the key primer but the alarm continues. The water pressure gauge shows normal pressure for running it on the hose.

I'm wondering if this is a fault in the alarm system, as opposed to a real warning alarm. I'm thinking a short somewhere?

If so, how would I go about trouble shooting it?

Thanks for any advice you can give.

 

[seahorse5]

Re: 1990 V6 constant alarm immediately at startup

A common problem is the electronic failure in the oil tank pickup assembly. Disconnect the oil tank tan wire at the motor and see if the alarm stops. Another item is a stuck vacuum switch, disconnect that tan wire to see if the horn stops. It could be a bad warning horn if it has the black wire attached to it - that is for the self test horn. Disconnect the black wire only and see if the sound stops.

The other things to disconnect to see if they are the problem are the "VRO" 4-wire connector and each cylinderhead temp switch - the tan wires.

 

[d.boat]

Re: 1990 V6 constant alarm immediately at startup

A common problem is the electronic failure in the oil tank pickup assembly. Disconnect the oil tank tan wire at the motor and see if the alarm stops. Another item is a stuck vacuum switch, disconnect that tan wire to see if the horn stops. It could be a bad warning horn if it has the black wire attached to it - that is for the self test horn. Disconnect the black wire only and see if the sound stops.

The other things to disconnect to see if they are the problem are the "VRO" 4-wire connector and each cylinderhead temp switch - the tan wires.

Thanks.

I have a OEM shop manual and have messed with the systems having installed the VRO pump and tank and have tested the alarms for "normal" functioning in the past. I'm pretty sure I can find the tan wires you mentioned. I was guessing that would be what I'd be doing.

The one thing I haven't messed around with is the warning horn itself in the control box.

Is it hard dismantling the control box enough to get at the horn and the horn wiring itself to check for a malfunction or ground fault there? I can't really tell from the repair manual without actually getting into it .... which I'll do when it stop raining!