Logo
FULL SITE MENU

Oil pressure/ temp alarm

B

brianda

New member
I just finished wintering my starboard 1978 318 chrysler this weekend, all went well until later in the day when I realized that the buzzer/alarm did not come on when i turned the ignition switch. The other gauges worked and the started turned. Can you give me any advice on how to trouble shoot this, I do like having the alarm. Thanks for any suggestions.
 
My crusader (1987 5.7 270HP) has the alarm box behind the helm. If I remember correctly the purple wire from your harness is the one that completes the circuit for the buzzer. I would assume you must have bumped a wire while winterizing. I'd check those to make sure there tight and then check your alarm box.

Good luck.
 
The alarm/buzzer is typically fed 12VDC from the ignition switch to one terminal and then is activated by a switch turning on to complete the circuit (to ground). typically, there are multiple switches in parallel, so that any one may excite the alarm.

When the engine isn't running and the key is turned on, the only switch that should be 'on' is the oil pressure switch, on the engine block...
 
The buzzer gets voltage from the ignition switch and is grounded by a spring-loaded switch on the engine. The most common failure mode is the ground wire losing continuity with the pressure switch due to a loose nut holding the wire on the switch stud or a corroded connection. You can check the system by disconnecting the ground wire from the switch and touching it to ground (ignition switch on - engine not running). The buzzer should sound. If it does the problem is a bad pressure switch or the connection to it. If the buzzer still does not sound the problem may be no voltage to the buzzer, a bad buzzer, or a wiring failure. Hope this helps.
 
Back
Top