I'm not getting the warning horn test beep. Question about testing horn.

[Bumblebeeman]

I have a Bumble Bee bass boat I recently switched motors on. I took off a 1991 XR4 150 with the original oil injection still working fine and put on a 1996 200 EFI that had already had the oil injection removed. On first start up I got the constant alarm and found out I had to disconnect the wire sending the there's no oil alarm. The boat I took the 200 EFI off of had one of the wires to the warning horn cut - maybe that's how they fixed the constant alarm. I later had an overheat situation and the overheat alarm went off properly. But now 9 months later, when I put a double-ended alligator test wire clipped to the tan wire connection at the engine (without disconnecting that connection) and touch the other end to a head bolt with no paint on it, the horn does not sound.

I don't have the test beep at start up. My questions are:

Is the warning horn test beep at key turn only activated when the low or no oil alarm circuit is active such that if all you have is overheat, no test beep?

I disassembled the throttle shift and removed the warning horn to test it. I know it operates on 12 V. I want to put 12 V on it, but the leads are not labeled + or -. Does anyone know if it is the purple wire or tan wire that is positive?

or

Does anyone know if putting 12 V backwards on the warning horn will damage or ruin it?

[Dave Strong]

If the oil injection was removed correctly including removal of warning module you will no longer get the test beep on start up. Purple wire will have 12v key on, tan wire provides ground to make horn go off.

Dave

[Bumblebeeman]

OK I tested the horn and hooked straight to 12 volts, it beeps. The reason it doesn't beep when installed is I discovered the tan wire coming from the engine is bad or I am working with the wrong wire. Is the tan wire coming out of the boat side of the big multi-pin plug the overheat alarm wire or is it a different wire? I did notice that at the ignition its tan with a blue stripe. When I run my own separate wire in place of that tan wire from the engine to the horn and hook it to the tan wire going into the engine and measure voltage between that wire and the purple wire that attaches to the horn I get 0.0 Volts with the ignition off and 11.78 Volts with the ignition on.

Can anyone offer my guidance on if I am experimenting with the right wire and how to fix the warning horn? Another question - If the oil injection is removed and you don't remove the oil warning module, which the person who removed the oil injection years ago did not remove the module and I disconnected a wire the Merc mechanic told me to to fix the constant alarm, and if everything is hooked up correctly and the warning module is still in place, will you get the brief horn beep check when you first turn the key? If you don't how do you know the horn is working?

Thank you

[tlwjkw]

OK I tested the horn and hooked straight to 12 volts, it beeps. The reason it doesn't beep when installed is I discovered the "tan wire" (is a buzzer ground) coming from the engine is bad or I am working with the wrong wire. Is the tan wire coming out of the boat side of the big multi-pin plug the overheat alarm wire (yes) or is it a different wire? I did notice that at the ignition its tan with a blue stripe. When I run my own separate wire in place of that tan wire from the engine to the horn and hook it to the tan wire going into the engine and measure voltage between that wire and the purple wire that attaches to the horn I get 0.0 Volts with the ignition off and 11.78 Volts with the ignition on. (reason is tha purple is a "switched" 12v and goes to tha buzzer, tan is a ground, when sensor is closed, coming from motor..)

Can anyone offer my guidance on if I am experimenting with the right wire and how to fix the warning horn? Another question - If the oil injection is removed and you don't remove the oil warning module, which the person who removed the oil injection years ago did not remove the module and I disconnected a wire the Merc mechanic told me to to fix the constant alarm, and if everything is hooked up correctly and the warning module is still in place, will you get the brief horn beep check when you first turn the key? (without any thing oiler module related hooked up you WILL NOT get any self check beeps) If you don't how do you know the horn is working? (trust it, with key on ground tha tan at tha little plastic terminal, if equipped, or tha tan wire itself, buzzer will go off)

Thank you

get rid of tha module completely, its useless at this point.. all sensors that go to tha module are as well.. you can get rid of those also..

send me an email address and i'll send ya an oem manual on pdf that has your motor in it.....

[Dave Strong]

Tan wire coming out of boat side of harness should be for temp gauge, tan wire on engine side of harness should be for warning horn.

Dave