OK, I'm not an EE, and I also did not stay at a Holiday Inn Express last night. So I'm feeling totally clueless about this.

I posted an earlier thread about using a relay to get a 72 seatbelt warning system to work with later seatbelt receiver switches, instead of the 72/73 retractor switches.

The problem was that the receiver switches work the opposite than the retractor switches. Receivers provide a connection when the connection is made, the retractors provide a connection when the belt is fully retracted. So without modification, the seatbelt light would be on when the belt is inserted, instead of the other way around.

Below I've provided a diagram of the 72 seatbelt system, and how I've wired the relay in.

Now the problem - the relay doesn't seem to function the way I thought it would.

After the connection between the NC 87A, and 30 is made (ie. the light is turned on), the relay switch stops functioning. Let me explain some more. If I take off the 30 connector, I can insert and remove the seatbelt, and I can listen to the relay, and hear the switch move back and forth. But, if all the connections are on the relay, as soon as the connection between 30 and 87A is made, the switch will not move.

If I move the connection from 87A (NC) to 87 (NO) things work just like without the relay, but when the connection between 30 and 87 is made - there is a loud buzzing, like the switch is rapidly opening and closing.

So to me it seems like the connection between the 30, and 87A(or 87) terminals is interfering with how the internal switch is being thrown.

*EDIT* Could the problem be that I'm splicing in the source for the 30 connection from the curcuit before the first switch? Later today, I'm going to try removing that connection, and replacing it with a connection from the battery.

So, if anyone understands what is going on, I'd really appreciate the help!

Thanks,
Matt

 

The problem was that the voltage for the trigger was getting to low.

The trigger was coming from the switch in the receiver, so I removed the connection from the circuit, and connected it to the battery +, and everything started working as it should.

Here's what I came up with.