seat belt light

[1ol72charger4me]

Here's a interesting question . How can I make the seatbelt light work in my 74 without hooking up the seatbelt interlock? I want it to come on when I start the car and stay on for 3-5 seconds and go off. Yes I know I could put it on a toggle switch, but I want it to do it automatically. Some sort of a relay?

[Nacho-RT74]

there are some considerations on this. On 74s there is an interlock control unit box what beside being the seatbelt interlock system to block the starting procedure if seatbelts aren't fastened, is also the brain to control every buzzer and warning light. So this control box controls THE LIGHT AND THE BUZZER... also uses one pieze buzzer for all the warning buzz function ( key, lights on and seatbelt )

on 72/73, the seatbelts warning light and buzzer were relay controled but not interlocked with a control box. This relay linked the actual seatbelt status through sensors ( similar on 74s ) with the warning signals. These models used 3 diff buzzers on each function... key, lights on, seatbelt

However, 71s used the time flasher device for the seatbelts without buzzer, and buzzers where just used on key and lights on. 71s didn't got seats and belts sensors like laters

In conclusion, yes is posible. Being 71s where made in that way. Depending on your electrician skills these are the options:

-change your complete underdash harness for a 71 B body, what will require also some wires turned around at bulkhead to match with engine bay disposition. Also change the wiper switch plug ( just the plug, prongs disposition changes between 71 and the rest ). This won't require splices or any special electrician job beside MAYBE juts a small splice job on driver side door jam switch.

-make splices on harness to re-route the seatbelt source. It can be done removing cluster and radio to get access to the right wires to make the propper splices. ALSO get the harness pigtail for the propper flasher ( pictured ) what is still as far I know available at dealres, since 90s Mopars still used them:



get the flasher and pigtail won't be necesary if your car it is equipped already with ign switch courtesy light SINCE is the same piece. 71s used this flasher for both functions at the time, note the next accesories diagrams, check the first one and despite the low fuel accesory on it.




Now, IF YOU ASK ME, I would go on the 71 harness route to keep untouched your actuall harness. Beside that, re-route the seatbelt light source won't modify the buzzer function still working linked to interlock box, unless some other mods.

Also we need to consider on 71s the seatbelt light was positive source switched on/off, and 72 and lates was negative source switched on/off

You can also remove the interlock system from your actual harness and convert it on earliers setup. Will require a splicing job on bench ( not on car ) for comfortably and easier job, but once again, if you ask me get the 71 harness is A LOT easier. This also will make you forgeett about the interlcok controls ( IF your car still has it in working order ).

even is true make the splices to change the light source is maybe less consuming time, change the harness makes a cleaner job. Note than I'm a stupid guy what HATES splices and mods or dirty splices all around out of the stocks setups. Take that in mind when you read my opinions LOL

all in my description is talking about a NICE, CLEAN AND USING THE ORIGINAL FACTORY PIECES

[1ol72charger4me]

Thanks for the great info! I wondered why none of the other buzzers worked. I don't like to cut and splice either so the 71 unit may be the way to go. The interlock switch is completely missing under the hood. The wiring is there and I've located a NOS switch but still need the bracket. Would all 71's have the harness or just those that were equpped with a certain group of options? I may be better off working on the interlock system to get it working correctly. I just remember my Dad having a 75 LTD that wouldn't start if anything was laying in the seat and wanted to avoid working on something that may have not worked right from the beginning.

[Nacho-RT74]

the reset button on engine bay is a diff stuff than the INTERLOCK CONTROL located down the dash ( in between the glovebox and ashtray receiver ), although related. Is to RESET the starting block in case of interlcok box failure or for some mechanical repair whast doesn't requiere to fasten the seatbelt to crank the engine.

Key in and seatbelt buzzer on 74s ( also on 72/73s but just for seatbelts ) is a plastic piece normally yellow but I have seen them blue. Is located at a passenger side of glovebox, attached at dash frame It could be unplugged or damaged. Its JUST ONE buzzer piece. This is for standart buzzers cars ( lights on and seatbelts for 74s ) Note the lights on buzzer cars equipped uses a diff buzzer than the standart JUST belts and key in buzzer equipped cars BUT shares same plug and location. Just the buzzer itself is diff. If you want to add on your car the lights on buzzer, just need to change the buzzer device and will have three buzzers in one. Of course will require to keep your interlock system

If you change for 71 setup, seatbelts doesn't have buzzer anymore, and lights on buzzer uses a pigtail and a buzzer for it, but harness itself has the provision to attach the pigtail so then the buzzer ( harness pigtail for lights on warning buzzer can be easilly home made ). Key In buzzer is the same horn relay, but with one prong more than your 74 has. Plugs into the same location, and the extra prong gets the extra source already on fusebox in to every 71/73 model

all this info can be some confusing, If you need more details just let me know

The seat sensors have diff sensing rates depending on which car was mounted... there are specifically 4 kinds of them, plus a diff one in the middle for bench cars. If extremelly sensitive, the sensor can be changed for one less sensitive... however dunno which one is less or more sensitive LOL.

replacing the underdash harness will make to get unused the harness down the carpet for seats and belts sensors, and sensors itself of course