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1974. the seat belt interlock.

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purple72Gremlin View Drop Down
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    Posted: Apr/04/2018 at 8:12pm
Does anyone have the information to bypass this interlock system?  my car isnt getting power to the solenoid to activate it.   dont say its easy. because in my cars case, the original owner took the seat belts out, and the fasten seat belt light stays on even if the key is out of the lock cylinder.  so I have issues that isnt normal.  the starter has been replaced with a reman, and it works, and the solenoid I replaced last year, (with a blue streak one)....

I also have the 1974 and 1975 TSMs.  

I am not good with wires. I hate wires. but I want to figure this out.  I dont believe the ignition switch is the problem. 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 8:47pm
If I recall the interlock didn't stop power but supplied ground to the solenoid. 
That's how the seat belt interlock and NSS are tied together in 73 - they supply starter relay/solenoid ground as there's a spade on the back unlike the earlier ones where the NSS blocked power to crank.
At least 73 it's the solenoid ground that's controlled, not power to the solenoid. 
I'd have to double-check the 74 diagram to see if it's the same as 73..
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 8:59pm
Very late 73 has the interlock.  you had to buckle the seat belt to activate the starter.  late 73, 1974, and early 75 has the interlock system....  there was a legal bypass so you could start the car without buckling the seat belt, and the fasten seat belt light would remain functional.    I think the logic module is my problem... 

I also have the 1973 TSM.   and the 1973 supplement, and its a very late supplement as it describes the interlock system, and the changes to the late 1973 Gremlin, which is basically a 1974 Gremlin.


Edited by purple72Gremlin - Apr/04/2018 at 9:06pm
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 9:01pm
Originally posted by billd billd wrote:

If I recall the interlock didn't stop power but supplied ground to the solenoid. 
That's how the seat belt interlock and NSS are tied together in 73 - they supply starter relay/solenoid ground as there's a spade on the back unlike the earlier ones where the NSS blocked power to crank.
At least 73 it's the solenoid ground that's controlled, not power to the solenoid. 
I'd have to double-check the 74 diagram to see if it's the same as 73..
My car has the 3 spd.  no ground at the solenoid.  and Ive already checked to see if Im getting power to activate the solenoid, no power.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote ramblinrev Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 9:38pm
Mine simply had the seat sensors unplugged when I got the car in 1977. If your bypass switch is intact (under the hood on the right inner fender) you can force the plunger down with the right size screw or bolt and leave it in place.
Or, you can figure out from the schematic which wires in that harness you need to permanently jump, and unplug that bypass switch.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 9:46pm
rev - is that bypass simply a relay that handles the solenoid ground circuit?
I'd have to check the schematics for that car and year but if I were to design such a system, I'd run the NSS circuit through the seat belt system using a relay - the NSS would ground the solenoid IF the seat belts were fastened, closing the relay circuit and allowing the NSS to ground the solenoid.
The seat belts not fastened would mean the NSS circuit wasn't complete. A bypass could simply be a means to force the relay closed momentarily.
That's a guess........... if I am correct then a blue wire from the NSS would be passing through that seat belt system.
Anyway, that's how I would design it to keep it simple.
I don't have the TSM handy to look at.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote billd Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 9:49pm
OK, just read that again - the stick didn't use the NSS to ground the solenoid. Then it's likely the seat belt relay closed the circuit for the S on the solenoid.
Key to seat belt relay - find that relay and connect the proper terminals - again, i'd have to look at the TSM schematic but it should operate in a similar way - except they feed the ignition switch S feed through the seat belt interlock system, a relay. That red button would bypass that relay.
So the solution would be simple - IF you knew which wires to jump - and if I had the TSM with me I could find that and draw it up.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 10:02pm
Im going to look at the tsm again.  been too busy.  the relay in the engine compartment has a button on it.   Im going to do more checking. and I need to make sure the ignition switch isnt the problem too.  
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Post Options Post Options   Thanks (0) Thanks(0)   Quote purple72Gremlin Quote  Post ReplyReply Direct Link To This Post Posted: Apr/04/2018 at 10:16pm
Originally posted by ramblinrev ramblinrev wrote:

Mine simply had the seat sensors unplugged when I got the car in 1977. If your bypass switch is intact (under the hood on the right inner fender) you can force the plunger down with the right size screw or bolt and leave it in place.
Or, you can figure out from the schematic which wires in that harness you need to permanently jump, and unplug that bypass switch.
Ive had several different 1974 cars. unplug the seat sensors and it disabled this goofy system. but in this Gremlins case the original owner got rid of the seat belts!  Im just going to have to figure out which wire is which and fix it somehow
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Post Options Post Options   Thanks (0) Thanks(0)   Quote 6PakBee Quote  Post ReplyReply Direct Link To This Post Posted: Apr/05/2018 at 8:38am
I have no idea what an AMC seatbelt override box looks like.  But as a former owner of a 1974 Dodge Dart I do have some experience with Mopar.  For them, you tie the two yellow wires together at the box and you are done.  I opened the box up and internally connected the two to make it look clean but I'm kind of anal sometimes.


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