So….this was a dumb little project I came up with a few years ago. I dunno about you guys but I tended to leave my parking lights on frequently after parking (no pun intended) seeing as these cars don’t have a reminder till 80 or 81 so I came up with this.
I had it posted before the crash and I’ve thought about reposting it but two things stopped me. #1 I discovered the little diagram I made last time is different than how I actually ended up wiring the buzzer and my attempt had one annoying drawback I didn’t fix till recently. The short version is due to back feeding, and the circuits I tapped into, any time I had my key in the ignition with the ignition off, I’d get a slight hum out of the keyminder buzzer even with the door closed. With it open it worked the right way. Unfortunately I haven’t had time to dig out my laptop and make a new diagram and I haven’t figured out an easy way to do so on my phone so for the time being I decided to type it out thinking anyone who wanted to try this could draw it out themselves in the meantime. Here it goes….
I used a spare seatbelt buzzer I had. These have 4 terminals. Two are for the buzzer sound and the other two become part of the telltale light circuit and the timer to kill the buzzer and light. For these purposes just use the outer two terminals for the buzzer only. The only other things you need is a 5 pin relay (with an 87a terminal) your favorite wire, spade terminal connectors and a diode. I picked one up from Amazon. Painless Performance 80111 Replacement Diode Assembly for Race Car Switch Panels
https://a.co/d/7DWiYdh I think it was a little cheaper when I bought it but you could probably find a cheaper one if needed.
First things to do is with your relay. Pin 85 goes to any keyed ignition source. I used one of the center blades on the fuse box that is keyed power only. Pin 86 gets grounded wherever you like. These will now trigger the relay any time the key is cycled to the “on” position. For those who don’t know how a 5 pin relay works, with 86 grounded and 85 energized, a switch in the relay closes between pin 30 and pin 87. When the relay is at rest, the switch between 30 and 87 opens and subsequently closes between 30 and 87a.
For this project pin 87 should remain unused.
Now, pin 30 will want to go to the left door striker wire for the dome light. This is a black wire that goes to the large connector on the bottom of the steering column. The reason for this is when that striker switch is closed it provides a path for the keyminder buzzer to sound when the key is in the ignition and the drivers door is open. We want that wire so the headlight buzzer only sounds when the drivers door is open and not the passenger side. That is also part of the reason why I had my issue with the key buzzer sounding even with the door closed. So at this point when the key is off, the relay is at rest effectively connecting 30 and 87a so when the drivers door is open a ground path is provided from the striker switch to pin 30 which is closed to 87a.
That leaves us with what to do with 87a. That should go to the negative side of the buzzer so when what I explained above takes place a ground path is established to the negative side of the buzzer.
Lastly, tap one of your grey illumination wires under the dash (I think I used the one to the heater controls) and run that to the positive side of the buzzer.
Now, bear with me, when you turn your parking lamps or headlights on, dash lights illuminate and provide power to the positive side of the buzzer. If your key is on, regardless of your door being opened or closed, the relay is energized and pin 87a is now not connected to pin 30 opening the ground path. Buzzer doesn’t sound. With lights on and your key off, buzzer gets power from the lights, the relay is at rest meaning 30 and 87a are connected closing the ground path except that path is opened at the door striker if your door is closed. Buzzer doesn’t sound. Open your door with the above circumstances and the circuit becomes completely closed and the buzzer will sound reminding you “Hey dummy, you left your lights on”.
You might be wondering where the diode comes in. I won’t explain how but because of how the key minder buzzer is wired and what you tap into for the headlight buzzer as I said above, the key buzzer will sound as it should with the door open and sound quietly even with the door closed to to a back feed condition. Take the diode and put the somewhere between pin 87a and the negative buzzer terminal. You may have to flip it one way or another. One direction will prevent the headlight buzzer from working correctly but the opposite direction will stop the back feed condition and everything will function as it’s intended.
I plan to still make a diagram one of these days but I hope in the meantime this wasn’t too confusing. It sounds more complicated than it is and with some splice connectors it’s minimally invasive and reversible if needed. Again, just a dumb project I wanted to try and it comes in handy. It’s saved me from leaving my lights in a few times.
Any questions ask!
