1989 International 8300

[klosterphobik]

Need help troubleshooting. the low air warning buzzer does not come on when the low air warning light does. it should happen at some point above 60 psi. i need some guidance on where to start trying to figure this out, i need to fix it soon.
additionally when i turn the key to the on position (not starting the truck) the buzzer activates and continues to buzz until the truck is either started or the key is turned back to the off position. to my understanding, the buzzer should turn off after a few seconds. Could this have something to do with my previous question?