"Phil.... If that 3 wire VRO i
"Phil.... If that 3 wire VRO is working okay, I wouldn't be concerned about it. I don't recall if the 1990 have the automatic horn test or not... whereas you turn the key on and the warning horn would momentarily beep to show that the horn does indeed work. If your engine doesn't have this feature, do not start the engine but have the key in the on position. Then ground out the tan wire that you'll see leading out of the cylinder head (heat sensor). This will complete the warning horn circuit which will cause the horn to sound off. If the horn doesn't engage, find out why.
The 3 wire VRO had a habit of causing a false alarm whereas it would sound off but nothing was wrong. The 4 wire VRO eliminated that problem. If your warning horn setup is okay, and the horn works.... and you have no false alarms, I see no reason to replace that expensive item.
NOTE.... If you ever want to do away with the VRO setup, simply cut and plug the oil line leading into the engine, then mix the 50/1 oil with your fuel (1 pint 50/1 oil to 5 gallons gas).
Joe (30+ Years With OMC)"
