1974 duster seat belt interlock module removal

Discussion in 'Electrical and Ignition' started by robert flippo, Jun 13, 2018.

  1. robert flippo

    robert flippo Well-Known Member

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    I stripped all wiring from my duster and in the process of rewiring under dash and engine compartment, i removed the reset button on inner fender, but under dash module was bad corroded , found another, it was corroded also, searched web, tells you to disconnect under seat, all that wiring is removed, told of a way to cut 2 yellow wires and by pass module, but the module has a lot of wires going into a bunch of corrosion, is there a way to cut out module and remove module completely ? part number is 3746849 and shows a build date 0914. My main concern is the amount and size of wire into the module, just seems overkill if all that did was stop you from starting car until seat belts was buckled.
     
  2. Johnny Mac

    Johnny Mac www.blueprintengines.com FABO Vendor

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    The interlock just needs unplugged from the seatbelt under the seat to no longer function. I'm pretty positive that I traced mine back to the dash and pulled the floor harness eventually...and I don't recall having to splice anything. But for all I remember the floor harness may still be under the carpet. I am 100 percent positive though that simply unplugging it, disables it.
     
  3. robert flippo

    robert flippo Well-Known Member

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    i am replacing all wiring, and wiring to seats disappeared 2 years ago,i got voltage at coil and have voltage at ballast, can start car at starter relay by crossing it over, burt cant get it to turn over with key, i dont have safety neutral switch hooked up, but i don't think that would stop cranking by key if i can cross it at starter relay, the car had the aluminum relay on inner fender that you had to reset it if it wouldn't start , it had 3 wires going to it, i think thats where they said you coud cut the yellow wires and wire directly to starter relay and remove it, but all that corrosion is green in that module under the dash and i have no ideal what all those wires go to,some are large gauge and they want $60 on ebay just for a used module, and i'm not sure that would cure my problem
     
  4. robert flippo

    robert flippo Well-Known Member

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    Stripped all wiring out from under dash and engine about 2 year ago, started rewiring,car wont crank with key but can cross it over at starter relay ok, have voltage at ballast and coil,the reset button for seatbelts on inner fender, i removed it, said you could splice the yellow wires and remove that relay, but under the dash my wiring harness has a module name seat belt interlock ,has lots of corrosion and lots of wires some larger than others, i know in years passed that you could disconnect seatbelt switch under seats, but the wiring has been removed for 2 years, no longer wires there, my question is, 1973 thru 1975 is the only years they put those modules under the dash because they gave so much problems, does anyone know if these modules can be removed and wiring spliced, part number is 3746849, date0914
     
  5. 67Dart273

    67Dart273 Well-Known Member

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    That is all pretty darn difficult to read. All you need to do is bypass the reset box under the hood. The two yellow wires going to that connector are in series with the "start" wire from the ignition switch on the way to the starter relay

    Looks like this thing, it's in the engine bay

    Won't crank

    100_0894-jpg.jpg
     
  6. robert flippo

    robert flippo Well-Known Member

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    what about the module under the dash, with all the corrosion, is that part of the seatbelt lock system as well? when i put the part number in, it shows seat belt interlock module
     
  7. 67Dart273

    67Dart273 Well-Known Member

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    ^^Did you read my post above^^

    ALL YOU NEED TO DO is bypass the reset relay

    and YES you need the neutral safety switch!!!!

    Go to MyMopar and download yourself a factory service manual. Closest you will get there is a 73, some wiring is different. Then go over to the wiring section at MyMopar and download the 74 diagrams, which are better than nothing.

    HERE IS HOW the neutral safety works

    On a "non" seat belt interlock car the functional path is:

    From the "start" contact on the ignition switch, with the key in "start" power goes out through the bulkhead connector, and to one of the PUSH ON (flag) terminals on the starter relay.

    This is one end of the magnetic coil in the relay

    Through the relay coil, and to the other "push on" (flag) terminal

    On an automatic, the other flag terminal wire goes down the firewall to the reverse / neutral safety switch on the automatic, to the CENTER terminal. The switch GROUNDS that center terminal in park or neutral, completing the circuit

    On a "stick" car that wire goes back into the interior through a separate grommet (one single wire) and to the clutch pedal switch, which grounds when the clutch is depressed
     
  8. robert flippo

    robert flippo Well-Known Member

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    Did you miss the part where i keep saying module is corroded bad and contacts are green and white stuff between the solder joints where water has been in module, it shows this module could control up to 11 different things from dash lights, dome light,door ajar and no one can tell for sure what all this module controls,thats why i dont want to do this all over again in a year and have to tear the dash apart to rewire,trying to make sure what all is contolled thru module, 1975 duster manual don't go into detail what happens if you remove this. theres a plastic module next to fusebox that is green with corrosion.and thats when i put the part number in and it says seatbelt interlock module, it said 74 was the 1st year they used it and they quit in 1975 because people had to keep getting out and opening the hood to reset the relays you showed
     
    Last edited: Jun 13, 2018
  9. robert flippo

    robert flippo Well-Known Member

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    ok , but can you tell me what the module controls, its full of white pwder and green with corrosion, don't want to put new wiring in all that corrosion, i know it will cause problems down the road , it looks like it has been wet. thanks,,,i will check the manual
     
  10. robert flippo

    robert flippo Well-Known Member

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    here's the part and connectors,have tried to clean, it hard to see in the photo but theres white corrosion on contacts and all in the module, that was why i was trying to find out what this module controlled

    0613182127.jpg

    0613182126.jpg

    0613182128a.jpg

    0613182126a.jpg
     
  11. robert flippo

    robert flippo Well-Known Member

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    here is one for a 75 model and i found one for a 74, and they have them listed as seat belt modules,that's why i ask if it can be removed, can't find them for 76.said mopar sent out notice to quit using them 0613182153.jpg
     
  12. 67Dart273

    67Dart273 Well-Known Member

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    What I'm trying to tell you is you don't need any of that. Unless you are trying to make it all work?
     
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    • robert flippo

      robert flippo Well-Known Member

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      i,m wanting to remove entire module, but if i cut the wires i have been reseaching, the dome light dont work, key in ignition will not buzz to remind you to take key out, door ajar will not buzz , and i wnt to make sure d4 i start hacking on my wiring harness, so that means if the module is bad or goes bad that i will have to remove all the wiring if i leave the module in, ma mopar saw what a cluster f*** they made when they added these in 1974b and 1975, and by 1976 they sent out the order to quit using them, i checked 2 other wiring harness i have, a 1971 dart and a 1976 duster, niether one of these have the modules. If you can find a orange one from canada or a green one, they done the by pass inside and you dont have to do the bypass on the fender well. Problem is finding one the right color that is good and not corroded , thanks for your help, like i was saying i have 2 of the tan modules and both are full of white corrosion where water got to the soldier joints and i dont want to rewire this again ,want to get it right the 1st time
       
      Last edited: Jun 13, 2018