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Can someone confirm this relay/diode question?

I have a circuit I'm trying to wire that's got me somewhat baffled.

I created a crude diagram of what I have. It's posted on my website:

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Basically the alarm system sends out a pulse down the two wires to lock it and reverses the polarity to unlock them. Simple enough.

I want to be able to unlock the Rear Door (RD) actuator independently of the others with the negative pulse wire (in brown).

The problem that presents itself is that I don't have a constant circuit to complete with the one wire. The ONLY way I can see that I can get it to work would be to use a relay on each wire to the RD actuator after it splits from the other two. One for + and one for - and patch it into the wires going to the RD actuator.

That way, when the trunk latch release buttom is pressed on the remote, it completes the circuit to both relays, completing a circuit to the RD actuator in the correct polarity to unlock it.

I'm guessing I'll need diodes (1N4001/L) on the wires coming from the relays (I'd need one on each, right?). I can't really use diodes on the circuit itself, because of the reversing of polarity. From my mental tracing, I should be ok there without any more diodes. Heck, I may actually not even need the two diodes after the relays, because when they're not energized, the segment of the circuit should be open, and electron flow should go as desired.

The ECM is programmable, so I can tweak the length of the pulse to accommodate any syncronicity issues between the two relays, so I should be ok there.

It would have been a lot easier if they'd given a two wire programmable option on the ECM, but I guess it really would have been the same because they'd just have to use relays in the ECM.

So my question is... Will this work? I could do it the other way, but I'd rather leave the relays in a resting state as much as possible. I don't know if it really matters, but intuition tells me if you can accomplish something without electricity, it's the preferred way to do it :)

Joseph

Reply to
joseph
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More info.

Good news (I think). I tested the leads running to the RD actuator and they are both grounded when in a state of (neutral).

So here's my plan..

I'm going to determine which leads needs to be + to unlock the door and put a relay on that wire. When it's not energized, it'll be on the regular circuit, so it'll either be - in a neutral state or locking, and positive when all the doors are being unlocked, or just the RD.

I think this will work, but still I wonder if I'll need any diodes. I'm guessing not.

Anyone confirm this?

Thanks!

Joseph

Reply to
joseph

Before I do something like this in the big world, I usually breadboard the circuit and debug it on my desk. Saves a lot of grief later on down the road.

What I mean, is build a similar circuit on your desk. If it works on your desk, it might work on your vehicle.

Lg

Reply to
Lawrence Glickman

There are a couple of ways to accomplish this. One of the easiest, would be to purchase automatic lock actuators as if the vehicle didnt come with power locks. Then you could wire the auto trunk button to them. and still keep the original ones in place.

Keep in mind, alot of what you are trying to do will depend upon your vehicle type. Chryslers and some other models, use one wire to control the locking and unlocking of the vehicle. The control unit passes somelike 250 ohms to the wire and it locks. If it passes 800 ohms it unlocks. Your plan wont work if you have that type of system.

A great website for what you want is the12volt.com . There you can post an you can download the wiring schematic for your car.

If you had to, you could put a diode on each wire to the power lock motor. Then you could wire your relay for each leg. The12volt.com has all the info you need for wiring the relays.

Hope that helps Pat

Reply to
komobu

Pat,

I put all of the actuators in myself. It's a 99 Jeep Wrangler. I've been to 12volt.com. That's where I found out the type diode i'll need.

Thanks!

Reply to
joseph

Gee, I could not find anything on 12volt.com

All I got was a headache - awful site

Reply to
LoLo

Update.

After some scrutiny I decided to scrap the idea. What I did instead was add a couple relays and make a two pulse opener. Now I unlock the driver door with one push, and the passenger/trunk with the second. No diodes necessary.

Reply to
joseph

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