latched on/off setup

Hi folks, I need an assistance/suggestion regarding my setup. I have toyota innova (asian vehicle) and has aftermarket alarm installed. I has successfully make latched on/off relay setup from the12volt.com (the exact diagram is: https://www.the12volt.com/relays/relaydiagram62.html


I'm using the latched on/off relay setup to make my car behave similar to recent mercedes. I want to turn on the parker lights and my foglights to turn on when I unlock the car and turn off when I lock the car. Combined the after market alarm I'm installing has the ability to automatically lock the car when the engine started and foot brake engaged and unlock when the engine shut-off it has working just the way I want. The setup has been working fine although has some minor annoyance.

The minor annoyance is when the engine running, and I unlock the car using switch on the car(for example when picking up friend) the parkers and foglights also turns on. Although it automatically turns off when I hit the brake pedal since the door will lock automatically.

I'm thinking to add one additional relay to turn off the latched on/off relay setup when the ignition on. But I'm afraid there are some delay that may prevent the latched on/off setup from working properly when I turn off the engine. Maybe the relay causing a delay to power up the latched relay to process the negative trigger input from the alarm when the engine turn off? The additional relay setup:

30: fused 12v
86: ignition
85: ground
87a: to 12v latched on/off relay

I hope you guys can understand my explanation :) So, what do you guys think?

Initially, try diodes across the relay coils, 1N4004, bands towards the POS side of each coil.

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howie ll wrote:

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Initially, try diodes across the relay coils, 1N4004, bands towards the POS side of each coil.

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thanks for your reply, I will install diodes on the coils of relay as soon as I got them. I'm thinking to install a diode on the latched 12v output since I think it will be safer (the latched output will get 12+ input if I switch the fog light on.

Btw, I've added another relay to turn off the latched setup if the ignition on it's working just the way I wanted :) (Automatic on when turning off the engine still works)

update, I just noticed if my engine car on (or if I took out the fuse 12v input), I can't unlock the doors using the unlock button. It seems something interferes the unlock mechanism. If I press unlock on the door switch, briefly it unlock then lock itself immediately. This isn't happen if the engine switched off (or the latched on/off relay setup has 12v+ input). All functions behaves normally.

Is it because I'm not using diodes on the relay coils? Or when the relay not receiving 12+ on the coils it act as a conductor connecting the pin on pulse to turn on and pulse to turn off coils? (hence it can't unlock) making the central lock receieves the unlock and lock signals at the same time?

Another update, problem solved. I rewired the cut off relay to cut off ground of the latched relay setup instead cutting off the 12+ input.