another possible keyless entry beep option

so, growing ever annoyed with the lack of a sound when you lock the truck I have been thinking about this for awhile..

Electronics scare me and Im not that good with meters and such....Well, went out to lunch with my dad..we took his 99 Tahoe



I drove..we got to the restaurant, got out and I locked it. It beeped., but not like a toyota beep..but rather the HORN beeped




why not splice or relay a wire from the light that flashes when you lock the truck right to the horn?

I dont see any reason why it wouldnt work

 

You could, but then every time you turned on your lights, you would hear your horn. I do agree there has to be a way to do it....hopefully PB can chime in and offer up his advice.

 

If you connected the horn to the flashers and the door locks that would work even better... that way the horn would beep only when the lights flash at the same time as the doors locking. A transistors and a diode would do the trick.

Transistors are like electronic valves... there's an in, and out, and a control connection. Connect the flasher light to the horn like you said, but put the transistor in between them and the transistor's control connection connected to door lock circuit so it only allows current to flow from the flashers to the horn if the locks are engaged. There is a separate lock and unlock circuit so this wouldn't even go off when you unlock! Perfect.

Now to find a wire under the hood for the lock circuit...

 

Other than the it beeping when the lights are lit, I'd be concerned that the lighting circuit wouldn't have enough extra power to kick the horn. Might be fine, but it'd be safer to design the circuit to handle almost anything. Here's a circuit I've been designing to get back the beep. All the parts I got at Radio Shack. When I build it I'll list the parts I used. Attached is the schematic in case you want to take a stab at it. I added a switch to let the service guys kill it and the ign line disables the whole thing while the engine is running.

 

That's a fine drawing. Do you have a suggested parts list to go with it?
Like Radio Shack part numbers you would use and then let folks go on their own if they want to substitute? I only ask that because although there are thousands of products that technically would work. You probably had something in mind that would be good for the truck, ie for mounting and controlling. Thanks.

 

Did you guys check out the cheap/free mod thread? Someone already makes and sells a box that does that for around $20. Beeps when the turn signals flash when the key is off (so no beeping turning corners on the street), and has a switch to kill it if you have the engine off and hazard lights on. Simple 3 wire install.

 

Thanks. I will add in the part numbers once I finish and test. I thought about using the horn but decided it didn't need to be so loud.

 

Does anyone know if I could install an actual horn in place of the piezo alarm and have it work? Its just a plug in connector and I can always change the plug to fit the horn. I like a conventional horn for locking the doors instead of that toyota piezo beep

 

Just wondering if anyone has tried this?? I was thinking of trying the same idea but wasn't sure if there will be enough current to run the horn. I'm pretty sure that little piezo barely draws current so the wires leading to it are probably on a low amp circuit.