1983 headlight buzzer is connected to the dimmer

[1983G]

The car is a 1983 Glx convertible with a 460 transplant.
I have a little issue with the dual function buzzer. Somehow the buzzer is connected to the instrument panel dimmer circuit.
I have the wiring diagrams, the EVTM manual, and I am trying to find a link between the instrument panel dimmer and the buzzer. I have removed the gauges that I installed, removed and verified the door jamb switches. somewhere i have mis wired something. I believe that the two circuits involved are 85 and 19. I cant seem to find anywhere the circuits collide. I removed and replaced the buzzer with no difference. I have an extra light switch, which is my next move. Anybody have any insight?
Thanks

[Scott Peters]

Since that annoying buzzer sound it for:
Leaving keys in the ignition and or headlights on when the driver door is open,with or without the engine running., I think I would try replacing the headlight switch.
The only thing the dash lights have in common with your problem is that switch.
The headlight switches do go bad as they run full headlight current through them.
That’s my guess.

[1983G]

Since that annoying buzzer sound it for:
Leaving keys in the ignition and or headlights on when the driver door is open,with or without the engine running., I think I would try replacing the headlight switch.
The only thing the dash lights have in common with your problem is that switch.
The headlight switches do go bad as they run full headlight current through them.
That’s my guess.

I agree. That is the only common element that I could find.
Changing the switch today and we will see what happens
Thanks

[1983G]

Changed the headlight switch, no change in the buzzer/dimmer switch.

[gr79]

Buzzer is getting power. Common ground of buzzer behind IP linked to other components there?
Seatbelt buckle interrupts ground to buzzer when buckled.
Once had w/s wipers turning on whenever headlights turned on. Wiper switch was off.
Turned out to be one bad eyelet connector of several at the rad apron ground point screw above the left headlight.
EVTM does not show any connection to left headlight and wiper motor at that point but there was.

Had issues with rear light grounds too. Electrical can get weird. Good luck.

[1983G]

Making progress. Changed headlight switch, no change, Changed dual buzzer, no change. One pin on the connector to the dual buzzer had voltage, which would vary with the instrument panel dimmer. Circuit 85, which I believe, is just for the seat belt switch. I traced that wire back to the green connector in the driver side kick panel. Once I separated that connector, the dimmer and dual buzzer behaved as expected. that would tell me that the problem I am having is after the green connector in the kick panel..

[gr79]

79 Mustang and 85 LTD EVTMs both show same circuit 85 from seat belt timer buzzer to seat belt buckle.
Shows 85 is a part of dual warning buzzer wiring. One connector is at DS kick panel.
When buckled and buzzer is powered, seat belt buckle switch is open breaking the ground to the buzzer.
Always on could be a short to ground in 85 between the buckle and buzzer?

Edit:
Thinkin reconnect everything and temp disconnect the seat belt switch ground wire under the seat.
No ground= no buzzer. If still buzzing, disconnect 85 at the buzzer. Same deal, different section of 85.
Isolating sections of ground wire 85 between connectors inline after the green connector.

[1983G]

Update: I made 7 little extension cords using 2mm bullet connectors,and
plugged them all in, except for circuit 85, seat belt switch. It appears that all functions are working, parking brake dash light, marker lights, turn signals, brake lights, license plate lights, fuel gauge and back up lights, Unless i missed something, i am just going to remove the pin for circuit 85and let it be

[1983G]

And the dual function buzzer is not following the dash light dimmer