Over temp/Oil Pressure Alarm

Does anyone have an understanding of the reference alarm and associated wiring for Chrysler 318 engines ? Is the alarm, or any feature of the alarm capable of disabling the engine if an overtemp or oil pressure threshold is exceeded ? I was running my 72 Egg Harbor on Friday, all was normal, guages all indicated normal range of operation, 55 lbs of oil pressure, 150 on the temperature guage. Cruising at 3200 RPM then all of the sudden the engine cuts out and dies. Could not restart the engine, even though it cranked. But I did notice that the alarm buzzer did not come on when the key was in the run position which it normally does, nor did the temp guage and oil pressure guage work while cranking. I'm thinking something overheated, but the guages did not indicate a problem. Went to the boat yesterday, turned the key, the engine started without problem. I have the old Chrysler 318 operating guide with a rather cryptic diagram indicating that there is a potential to wire a 2 port, 3 port, and 4 port alarm system, but no details as to how, or where the components may be located. I'm trying to understand if the alarm has any active features to shut the engine down to protect it in the event of some overheated condition, or loss of oil pressure. I did change the temperature sending unit earlier in the season since the original had crapped out. Had a very difficult time finding a replacement.

Mike,

I would say you either have and ignition switch that is failing or a loose or corroded connection on the ignition terminal of the ignition switch. When the key is in the run position it sends power to the gauges, alarms, and ballast resistor so if that part of the switch or connection on the switch failed then your engine would die, alarm and gauges would not work when the key was in the run position. Did the engine still crank when you tried to restart it after it died? If not then the power feeding the batt terminal of the ignition switch would be your issue, if it did still turn over then the ignition circuit should be your problem.

Matt

The alarm does not kill the motors when something is wrong; it only makes noise.

Start checking the coil's voltage with a volt meter. You should see 8 to 9 volts with the key ON, and 12 volts when cranking it over. BOTH must be there for the motor to run.

Jeff

jeff,
any idea where its connected to on the console? i have mine disconnected and cant figure out were they run to. how can i figure out where they go? the wires dissapper to a point were i cant keep tracing them cause i cant see.