seatbelt buzzer wiring Options

[Dave_Darling]

The wiring diagram is available here:

http://www.pelicanparts.com/914/914_electr...al_diagrams.htm

The Dreaded Seatbelt Interlock Relay is on Page 4 of the 74 diagram, and is component J34.

The only power-in on the relay is on the following terminals:
15 (black wire) constant power.
L (yellow/red wire) switched power--after it goes through the warning light.
C (yellow wire) power when the key is in "start" only.
H (grey/yellow wire) switched power, which runs the "door ajar" buzzer.

...Come to think of it, I believe that "L" isn't actually an input, but an output for the light. When the relay grounds L, the light comes on.

I have a relay somewhere in my Stash Of Parts ™, but it'll take a long time for me to find it...

Basically, the relay does nothing at all but turn on the light and interrupt the signal going to the starter. The only wires going to it that are in any way important are the ones where two wires are crimped into one metal connector. If you want to take the socket out completely, then splice together any pair of wires that are crimped into the same metal connector. That will leave all the functionality of the car intact, except for the door-ajar buzzer, the seatbelt warning light, and the starter interrupt.

--DD

[Mikey914]

Ok, I'm missing the relay, so rather than waste my money buying another, I can connect The heavy yellows together, and then connect all double clipped wires together. Then secure remaining wiresou to of the way, correct? (IMG:http://www.914world.com/bbs2/html/emoticons/dead horse.gif)

[Rleog]

This may be a dumb question, but I really don't know: Where do the yellow wire go to. They are huge, I assume they are related to the start function. I don't recall seeing a yellow wire at the starter or solonoid. The pictures are great, hope to clean this mess up.

I found this thread very useful while reconditioning my wiring harness, which is out of the car. As Dave suggested, you can use the wiring diagram to answer Jim's question.

More easily for future users:

The Yellow/Red stripe wire originates on the Regulator Plate (Relay Board) within the 14 pin connector at terminal #1 then runs to the seat belt "Logik-Relais" (Bosch's nomenclature) The solid Yellow wire runs from the seat belt Logik-Relais to the steering column switch.

Thanks to all who contributed to this thread.

[Dave_Darling]

That's true for the 74 cars, and some 75s. The "Logik-Relais" is the Dreaded Seatbelt Interlock Relay, which was added in 74 as a DOT-mandated safety measure and then removed in 75 as a DOT-mandated safety measure. In earlier and later cars, the yellow wire runs from the ignition switch to the relay board without being interrupted by the relay.

The relay is a failure point; it is common to remove it and splice the two thick yellow wires together to bypass its function.

--DD

[r_towle]

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[jim_hoyland]

So, it relay works by ground to make current flow And the main grounds seem to be the seat belt and seat sensors. Anything else ?

[r_towle]

So, it relay works by ground to make current flow And the main grounds seem to be the seat belt and seat sensors. Anything else ?

Seriously dusty cells on this one….but
The work around is to ground all brown wires to the chassis.
Direct connect the large yellow wires that is ignition key to starter solenoid.

That solves the issues.