diode use in a car alarm

So i have my alarm, the relays and the aftermarket actuators ready. I understand that i have to use some diodes from what i have asked in the past. now that i have everything i would like to know where and why do i need, if i need to use diodes?

What alarm? What car (year and model)

oh ok .. zenesis zn-502r AS ... and the car is 2001 honda accord 4 door. The car has no factory alarm and no power anything. i decided to add acutators. in my configuration i will have one wire of all 4 actuators connected to the lock/arm output of the alarm and then the driver actuator second wire it will be at the unlock/disarm. the second wire of the remainign 3 actuators i will connect it with an auxiliary output. i think i will have to use one relay for the driver actuator and another relay for the other 3 actuators ... please advise. I will add a trunk solenoid that will be connected to the trunk release output. and i will have remote start using a fortin honda sl3 bypass. so i couldn't think to where do i need to use diodes. thanks.

Actually 4 relays and diodes. You will need 1 relay for lock all, 1 relay for driver unlock, 1 relay for other doors unlock, and 1 relay to power the trunk release solenoid. The diodes go across the coils 85 and 86 with the bands towards the coil positives 86 and are 1N4004. these are to protect the alarm from the coil onrush or spike when it shuts down. Read the sections on diodes and relays on this site. Strangely enough we ALWAYS had factory central locking on either UK build, 5 door Civics and CRVs or Japanese build 3 door Civics and Accords.

howie ll wrote: Strangely enough we ALWAYS had factory central locking on either UK build, 5 door Civics and CRVs or Japanese build 3 door Civics and Accords.

I don't know what to say. I will check tomorrow .. but i stopped recently there and they said based on my VIN that i don't have a factory alarm so i don't know if it has anything to do with the central locking. I will let you know what they will tell me.

so I have checked with the dealer. My accord is a dx and is US i believe and it has no factory keyless entry. so that's why i will install aftermarket actuators. now i was curious on that alarm the unlock and lock outputs are (-) so where do i connect that one on the relays ? to 85 ot 86 and depending on where i will put the outputs than where do i put the diodes ? i will try to make a small diagram of how i plan to install it and then we can go over how will i put the diode in ...

I'm confused, can you lock all the doors from the driver's door key? i.e. does it already have central locking?

no howie ... the dealer said that i don't have power doors or windows or seat or anything else in that car. It is the basic of the basic. when i unlock the car i unlock the driver and that's it. if i want to open the other doors i have to unlock them individually by pulling the pin on the doors. what i said is that i am installing an alarm on my car and that i will install actuators as well and also a trunk solenoid. I wanted to make a driver priority unlock, but that is on another thread and that is on the past. I will install driver priority or two stage using another auxiliary output, im good with that. now based on my drawing can u please tell me where and what direction should i put the diodes?

Thank the powers your diagramme is spot on! I don't have to do yet another . On a minor note a combined fuse of 30 amps for all the reds, i.e. the constants going to 86 and 87, use that to feed the trunk solenoid relay as well since they won't be used at the same time. One small point, the international numbering system makes 86 the coil pos. not 85. It won't effect what you do but the car manufacturers do it that way, so what ever side, 86 or 85 you send the 12 volt+ constant to place the diode between 85 and 86, soldered to the base of the terminal with the band towards the pos side.

For more info on above, go to the relay section on this site, go to "add auto lock and unlock" and look at the right hand relay, it shows the diode polarity and position.