Headlight Chime

[Phred]

I am looking to wire in a “headlights left on” buzzer/chime for my Model A and having challenges coming up with a wiring diagram to do it, as there are two factors to be met in order to trigger the buzzer: 1) the car must not be running (ignition key off) and 2) the headlights must be switched on.
In my case, the ignition key supplies power to the ignition coil as opposed to the original Model A wiring of having the ignition key interrupt the ignition ground.
For some of you with more electron management experience than me, this may be a relatively simple circuit. I would appreciate any assistance. Thank you in advance.
Peace, Phred

[MrBruce]

If you get it working be sure to let us less than knowledgeable electronic guys know the diagram.

[BruceKC]

You need a normally closed relay. Use the tail light wire to one side of the closed contact and the other side to the buzzer. Ground the other side of buzzer. Connect the coil side of the relay with the key wire on the ignition coil and ground the other side of relay coil

[CarlG]

1)Connect to the "on" side of the switch.
2)Connect to the tail light circuit.

At least that's the way mine works.

Here's a couple previous threads:

https://www.fordbarn.com/forum/showth...light=reminder

http://fordbarn.com/forum/showthread...781#post647781

[Tom Wesenberg]

How about a buzzer and diode wired in series, then connected to the generator output post and headlight wire. When the generator isn't putting out voltage (engine off) the headlight current would feed through the buzzer and diode then through the generator to ground. If the engine is running and the lights on you'd have 6 volts on both side of the buzzer, so it wouldn't buzz. When you are driving with the lights off the diode would block the current from going through the buzzer and lights to ground.

I'd go the easy route and just look at the switch to see the handle is down, and look at the lights to see if they are on.

[Jeff/Illinois]

Sponsored Links (Register now to hide all advertisements)

I unplug the one on my modern cars they get annoying!!

[Mitch//pa]

Originally Posted by Jeff/Illinois

I unplug the one on my modern cars they get annoying!!

on most newer cars the multi function chime module works with other circuits so unplugging it is most likely creating other issues... the better bet is to puncture the tiny speaker in the module.....

[silversink]

and what was Henry's part No. for that?

[Y-Blockhead]

Originally Posted by Tom Wesenberg

I'd go the easy route and just look at the switch to see the handle is down, and look at the lights to see if they are on.

That's the best idea yet Tom!!! Or you could look at the AMP gauge before getting out.

Or you could install a normally open push button switch in the door jam connected to the tail lights so you get a buzz when you open the door with headlight on. Use a switch similar to more modern (50-70) dome light switch.

[C26Pinelake]

I have got caught in fog on two occasions and each time I have forgot to shut the lights off ! To err is human !
Wayne

[MikeK]

For the visual learners...

[pooch]

Why is a diode even needed ?

In a standard positive earth system...

lights off no - from lights , + from genny earth, no sound.

lights on, engine running, - from lights, - from genny charging, no sound.

lights on, engine not running, - from lights, + from genny earth, buzz.

[CarlG]

Originally Posted by silversink

and what was henry's part no. For that?

a-54448-66

(a-lights-on)

[MikeK]

Originally Posted by pooch

Why is a diode even needed ?
In a standard positive earth system...
lights off no - from lights , + from genny earth, no sound.
lights on, engine running, - from lights, - from genny charging, no sound.
lights on, engine not running, - from lights, + from genny earth, buzz.

Without the diode the buzzer, a rather low-current device, will sound with the engine running and the lights off. The generator output will flow through the buzzer and then through the tail light filament as a ground path.

If the buzzer normally draws 25ma on 6V and the tail light 300ma on 6V you will see only ~8% voltage drop across the buzzer if the tail light is used as a ground path. 7.2V (running) x92% = 6.6V. The buzzer will be LOUD. You need the diode.

[pooch]

OK, thanks Mike, forgot about the bulb filament .

I know just enough about electricals to get myself into trouble.

[C26Pinelake]

Originally Posted by CarlG

a-54448-66

(a-lights-on)

A good one for sure ! Wayne

[MikeK]

Secret decoder ring.

[barnstuf]

I just look at the ammeter to make sure it is on zero when I get out of the car.
Simple solution!

[Phred]

The attached seems to be a diagram of BruceKC post #3.

A little bench testing, to satisfy my curiosity, with a SPDT 12 volt relay shows that it ought to work.

Thanks to all for your help

[OL JENNY]

If you are using a 6 volt alternator, where can you connect in order to have equal voltage on each side of a buzzer when the engine is running? My problem with leaving lights on is when driving in the daytime and using the lights on to be a little more visible. Mike K's schematic for a generator makes it clear, but is there a hook up for a 6 volt alternator?