Black box

Gerald - The alarm circuit design was poor, & prone to failure. The part is no longer made.   It is amazing that yours has made it this long before failing.

I recommend just disconnecting the module & watch your gauges instead.

Gerald,
I'd like to back up what Chris said. I think they were built by someone in high school shop class! Chris is the one who really knows about the alarms. so much that he and his son went and tried to build a better one after looking at the factory alarm. There's a complete thread on the build. Chris, I forgot but what ever happened to that project?

Gerald,
Didn't you have a brother? I haven't seen him on site for some time. What's he up to?

I am installing my new dash panel this winter and cleaning up the factory wiring job. My alarm was inop and the lights stayed on all the time so I just cut out all of the wiring for that device. I am a gauge watcher so there is no need for an alarm plus when it is super sunny those lights won't catch your eye anyhow.

The replicated alarm circuit my son built didn't work any better than the original.

The reason these don't work (they give false alarms) is that the brain of it is just an operational amplifier, which monitors the voltages of the oil & water temp sensors. Well, the voltage of the engine is not steady.
The circuit had a very poor voltage regulator design ( just a zener diode) so it was not stable at all & would falsely react to momentary dips in voltage.

I still have it if anyone would like it . . .

TAKE IT OUT AND SHOOT IT!!!!!!!!