hello guys,i just bought this boat and am going over maintence items before using it.im testing my warning system on my 1997 evinrude 115 90 degree cross flow with vro .when i turn the key on and test the system the led lights work and horn sounds for a moment[self test seems to work].when i ground out the temp sensor wires i can get the led light to go on but no horn .i also tryed this with the oil tank sending unit it also lights the led but no horn.i hooked up volt meter to alarm wires and get nothing even with the key left on for 60 seconds.what am i missing as i cant find this senerio in my workshop manual.thanks scott