The warning buzzer is going off even with machine off unless I unhook batteries, I can start machine and sometimes it will go away but come back on later. Only thing that puzzles me is no warning lights on dash for anything...have checked all fluids to make sure they are in operating range and all are good
Hard to say without wiring diagram. But check what part of circuitry comes to the buzzer direclty from the battery. may be a stuck relay. Or your ignition lock is not disconnecting all contacts properly. Wires rubbing together can cause this also. I don't think that machine will give out any audible warnings with the key out, so your fluids etc. are probably all OK. Probably something connecting buzzer or it's relay directly to the battery positive or ground depending on a layout of the circuit.
You're assuming the warning lights all work and/or getting good sensor data? I think I would proceed carefully. It could be something stupid like a seat belt switch, but it could also be something more critical. I would probably find the associated relay and verify the 'coil' of the relay is being fed power. this would mean something is firing the relay, not just a bad relay. Then you would need to work through the schematic to find out what fires it.
You have an old machine with wiring that deteriorates over time. First issue concerns your battery disconnect. Does it snap hard when you turn on the key and drop out when you shut off the key? If not you will need to start with that. There are two small wires connected to bars on the disconnect. Both are usually hot with the machine off. One of the small ones goes to the key switch. When you turn on the key it grounds the circuit and allows amperage to flow through a coil which pulls in the contacts to connect the batteries to the rest of the operating components of the machine. If you disconnect one of the small wires, the battery disconnect should not come on. There are issues of the battery disconnect being old and getting stuck. You can take it out of the machine and tear it apart to clean and check the internals. While you do that, you can also check the two small wires for being grounded. Make sure the key is off and check for continuity between the wires and the frame of the machine. If there is continuity, you will have to start chasing down the wiring harness looking for damage. If there isn't a ground you can then turn on the key switch and there should be continuity. Have you checked all the fuses for being good? I use a test light or and ohm meter for that. Many times the fuses look good but are bad. Let us know what you find.
All of you have given great things to look at...the buzzer sometimes will stay on even with the machine started and running and stays on when I shut the machine off until I disconnect the negative battery cable
When I read that last post, I think that I see that the machine will start and run and even shut off on the key. The battery disconnect then doesn't drop out?