Seat Belt Light/Buzzer

PADave

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I'm freshening up my 72. One of the things I always wanted to do was get the seat belt warning system working as it did from factory. The previous owner removed the buzzer and the light was broken. So, I got a new seat belt light and buzzer.

I started the car with seat belt off. Put it in gear and the light and buzzer comes on, perfect! I latched the drivers seat belt and it stays on :chin:

Nobody was in the passenger seat but I latched that one just in case. Still buzzzzz.

Has anyone diagnosed this type of problem? I guess I should start by looking in the seat belt retractor?

Thanks

 

jbojo

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I was thinking the wiring off the retractor might be disconnected or the connector needs reseating or the retractor is bad.

Edit: You can test whether the drivers seat retractor is working by disconnecting the connector and using an ohm meter touch one lead to ground and the other lead to the connector. You should have an open until you latch the seatbelt and then it should show continuity. If that is good then ground the wire going to the buzzer and see if the light goes out while in drive. If it doesn't you'll have to troubleshoot the circuitry to the buzzer for an open. Also ensure that the retractor has a good ground at the bolt and car body. It has to be the drivers side as the passenger seat has a seat sensor on that side of the circuitry so it wouldn't buzz anyway. Drivers side does not have that seat sensor for obvious reasons

 
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mrmach1

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Not too change the subject but does anybody know if the seat belt warning system was available with a manual shift? I have a 72 that has the system but has been converted from a Automatic to a 4speed and would like to get the warning system working again.

 
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jbojo

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Not too change the subject but does anybody know if the seat belt warning system was available with a manual shift? I have a 72 that has the system but has been converted from a Automatic to a 4speed and would like to get the warning system working again.
Looks like for a 72 the belt warning system was available after Dec 71. In a 72 it appears that they used a seat belt time delay switch for the light. From what I can figure out from schematics once you started the car the light would come on for a predetermined time and then go off and probably served as a reminder to buckle up. I don't see a belt retractor circuit system being used and the transmission position doesn't come into play.

For the 73 that's a different story, The manual transmission has a switch (auto use the NSS switch). The seat back retractor provides the ground to the buzzer and light as long as the NSS is in the reverse or drive position or on a manual tranny the switch is made. If the seat belt is used putting it on breaks the switch and removes the ground. Only difference on the passenger side is that there is a seat pressure switch in series with the retractor to detect the passenger. If it weren't there then you would have to buckle the seat belt whenever there isn't a passenger.

It would be interesting to hear from a 72 owner with the working seatbelt light to confirm or correct my conclusions for that year.

 
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PADave

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I was thinking the wiring off the retractor might be disconnected or the connector needs reseating or the retractor is bad.

Edit: You can test whether the drivers seat retractor is working by disconnecting the connector and using an ohm meter touch one lead to ground and the other lead to the connector. You should have an open until you latch the seatbelt and then it should show continuity. If that is good then ground the wire going to the buzzer and see if the light goes out while in drive. If it doesn't you'll have to troubleshoot the circuitry to the buzzer for an open. Also ensure that the retractor has a good ground at the bolt and car body. It has to be the drivers side as the passenger seat has a seat sensor on that side of the circuitry so it wouldn't buzz anyway. Drivers side does not have that seat sensor for obvious reasons
Thank you for the tips, very helpful. I will dig into it next weekend.

 

jbojo

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Thank you for the tips, very helpful. I will dig into it next weekend.

I am not sure if the 72 retractors have the switch now. I was going off a 73 schematic and I looked at a 72 schematic today and it's different. Let me know if your retractors have the single wire coming from them. If not I'll trace the wiring more thoroughly and may have some questions for you to help you figure this out.

 

PADave

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I am not sure if the 72 retractors have the switch now. I was going off a 73 schematic and I looked at a 72 schematic today and it's different. Let me know if your retractors have the single wire coming from them. If not I'll trace the wiring more thoroughly and may have some questions for you to help you figure this out.
Yes, there is a single wire going to both retractors and one going to the pressure switch on passenger seat. My car was built 4/72 in Dearborn.

 

jbojo

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I am not sure if the 72 retractors have the switch now. I was going off a 73 schematic and I looked at a 72 schematic today and it's different. Let me know if your retractors have the single wire coming from them. If not I'll trace the wiring more thoroughly and may have some questions for you to help you figure this out.
Yes, there is a single wire going to both retractors and one going to the pressure switch on passenger seat. My car was built 4/72 in Dearborn.
Ok then the first procedure should work for checking everything out. Check the drivers side first.

 
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