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fasten seat belt light. key in buzzer

midnightrider1818

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Hey guys working on a 73 roadrunner. Right under the dash above the gauges is a fasten seat belt light. The light is inop and was wondering if i could get some knowledge on how this works. I noticed the seat belt spools have two wires coming out of them that arent hooked up and i noticed my key in buzzer is not working. Not sure if these items are optional or if all cars came with it. Thanks guys
 
To my knowledge, both are standard items. Key in buzzer is not on the same circuit as the seat belt buzzer. There are two wires that run down the column to the connectors on the harness, red wires, that are connected to a switch on the ignition for the key in buzzer. if they are disconnected or the buzzer is removed or not operable, then it wont work. The key in buzzer is part of the horn relay on the fuse block under the dash on the fire wall.

The seatbelts on both driver and passenger side are interconnected as well as an occupancy switch under the passenger side front seat. All of these need to be connected for the light and the buzzer to work. Most people disconnected the seatbelt buzzer as its pretty obnoxious. The seatbelt buzzer is located on the passenger side dash next to the glove box, outer side above the kick panel. There is also a seatbelt relay, 3 prong under the dash, next to the ashtray.

here are a couple pictures of the seatbelt relay, hanging with the flasher, its the one with the bracket on it, and the location of the buzzer socket right side of the glove box.
DSC04218.jpg
DSC04219.jpg
 
thank you so much. I really appreciate your help. I will try to tackle this when I get time.

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ok got key in buzzer working. problem is whether the key is in or out buzzer stays on all the time. did a continuity test between the two red wires coming from steering column and there is continuity there whether the key is in or out. Im sure the switch is bad for the key. was wondering where can you get a new switch for that at and how hard is to change. where is that switch located. right behind the cylinder lock ??
 
It could also just be stuck on. I got a new one when I replaced my ignition switch, but that was through year one, about 3 years ago. I do see them all over ebay, some nos, not sure who is selling the reproduction ones. Either way, shouldn't be difficult to find one.

Here is a picture of the column disassembled showing the ignition switch and the key in buzzer switch.
IMAG0756.jpg
 
for 72 and 73 the system works like this:

-key in buzzer... is the horn relay itself ( same for 71 ). Gets a door ground just from driver side door switch ( black wire ). When opens the door sends ground to the column switch sensor switch. If key is IN the circuit is closed and makes buzz the buzzer. Buzzer gets constant positive

-Lights on buzzer... Gets door ground from same source than previous system. Gets the lights on buzzer. At the time, the positive source is sourced from light switch PARKING position. Once both switches are closed feeded both poles, the lights on switch will buzz. This buzzer is located just right at side of ashtray receptacle attached to dash frame.

-Seatbelt buzzer and light... Gets a relay ( pictured ) which gets two poles ( ground and positive, however the relay is chassis grounded too ) some like the lights on buzzer, just that the positive comes from RUN circuit ( blue wire ) and ground comes from NSS ( brown traced ) spliced from starter relay. Once Run circuit is closed and Ground signal from NSS is cut, relay sends GROUND retractors and seats sensors.

When retractor and seats sensors gets this ground meeting all the requirements, circuit keeps closed this ground to make buzz/light the seatbelt warning system. Positive is constant from RUN circuit on these.

This buzzer is a plastic one, attached to far right side on dash frame.

View attachment 268210

as you can see every buzzer is independient


in 74 everything of this was TOTALLY redesigned.

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for more ( although showing more functions being to Imperials ):

http://www.imperialclub.com/Repair/Lit/Master/294/index.htm
 
Hhmm mine is a little different. My seatbelt relay has 3 poles and my key in buzzer is opposite of what you said. It has power through the column switch and the ground is there all the time
 
So as Nacho points out, the 73 seatbelt light and buzzer stays on forever if the car is in the run position. So for a stock 73 car, you HAD to wear your seatbelt or constantly listen to the buzzer. This meant that many owners disabled them in various ways. For my car, the belts were simply rolled up and then slid back into the seat belt retractor.

Just be aware what you will have when you get it all back working!
 
yeap, relay is 3 poles... two inputs ( NSS ground and RUN positive circuit ) and the output ( comming from chassis ) to the seatbelts and seats sensors... once all the stages are met or not, the buzz and light will buz or not. So the first stage to makes seat and belts sensors get into the play, is you meet the fist stance... Key in RUN, sending positive to relay, buzzer and light at the same time. Once the car is geared cuts the tranny ground and relay clicks to the chassis ground to send constant signal to seat and belts sensors. IF, all switches are closed on sensors, the light and buzz will come on triggered by ground coming from Relay and made all the route through sensors

A relay needs both poles to work, no matter if sends negative or positive, that's the reason why gets the positive from RUN circuit to be activated.

The relay is normally open, but the trigger is the absence of the tranny ground, to send the chassis ground what the relay takes from its own chassis ( needs to be attached to dash frame ) once is closed getting the RUN power. This relay can be substituted by a regular 5 pins Bosch, setting up the wires correctly.

So if you have CONSTANTLY a ground arriving to buzzer and light, the sensors switches are allways closed, no matter if damaged or belts unfastened with somebody sat on seats. You can "cut" this ground, unplugging the angled plug into the driver side kick panel area ( blue and gray wires in it ). Both wires drives ground, just that one is send to sensors and the other one is the send to the buzzer and light.

YOU CAN GET a peeled wire cover too!!! not really a sensor damaged

The positive should come on once you set your key in RUN, nothing more nothing less.
 
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