Dual Relay Question: Car Keyless Entry and Secondary Module for in car unlocking

Thread Starter

chris4817

Joined Dec 30, 2019
5
I am in a pickle and can't get any solid answers. Here is my situation... My vehicle came with no power locks at all. I bought a kit, installed all the actuators (2 wire system), and everything with the keyless entry (Avital 2101L) works. However, for whatever reason, they did not add a wire in the harness to have a hard button inside the vehicle lock and unlock it. I have attached the diagram for the keyless entry system, and marked the two relay's wires with red and green dots. The second module allows me to use a button to trigger another relay to unlock or lock the system. I have attached that diagram as well. Will I be able to connect the outputs of the relays to each other (lock and lock, unlock and unlock) without any issues? or will I need to add diodes into it, to isolate the current from backfeeding the respective modules?

TIA!
 

Attachments

1577819249115.png

It looks like the alarm module is driving the lock motors directly?
In which case, I need to think about it.

in a vehicle that I installed an alarm system in I may have added 2 or 3 switches. The car did not come with locks.
1. VALET mode in conjunction with ignition ON.
2. Enable unlock of passenger door. This turned out to be useful.
3. May have been Lock and unlock
4. Added a "pull the door handle" sensor alarm, so you never had to actually break in. "Trying the door handle" was enough,

The NORMAL door motor lock and unlock relays normally connect the motor to common of the relay. The NC contacts get connected to ground. The NO contacts to +12.

Activating both or not activating both relays have the effect of shorting the motor which dynamically brakes the motor. It stops instantly, it's a generator operating into a short.

If you are doing this externally with your own relays, it's easy. The relay activation can be a connection to +12 or a connection to ground. Your choice. You just parallel the alarm connection.

You do have a lock and unlock input. You have Violet and Violet/black.

In general, the (-) usually means a - trigger or contact to ground.

You can buy a dual relay harness (one per lock) with most of the pins wired from parts express. I put that in the door.

So, did you install your own relays?

I need to think about it some more after having your answer.
 

Thread Starter

chris4817

Joined Dec 30, 2019
5
View attachment 195748

It looks like the alarm module is driving the lock motors directly?
In which case, I need to think about it.

in a vehicle that I installed an alarm system in I may have added 2 or 3 switches. The car did not come with locks.
1. VALET mode in conjunction with ignition ON.
2. Enable unlock of passenger door. This turned out to be useful.
3. May have been Lock and unlock
4. Added a "pull the door handle" sensor alarm, so you never had to actually break in. "Trying the door handle" was enough,

The NORMAL door motor lock and unlock relays normally connect the motor to common of the relay. The NC contacts get connected to ground. The NO contacts to +12.

Activating both or not activating both relays have the effect of shorting the motor which dynamically brakes the motor. It stops instantly, it's a generator operating into a short.

If you are doing this externally with your own relays, it's easy. The relay activation can be a connection to +12 or a connection to ground. Your choice. You just parallel the alarm connection.

You do have a lock and unlock input. You have Violet and Violet/black.

In general, the (-) usually means a - trigger or contact to ground.

You can buy a dual relay harness (one per lock) with most of the pins wired from parts express. I put that in the door.

So, did you install your own relays?

I need to think about it some more after having your answer.
The relays are inside the keyless entry module and directly drive the actuators via 2 wires. Does this answer it?
 

MisterBill2

Joined Jan 23, 2018
5,753
I see that the module does have lock and unlock inputs, so use them and don't mess with additional external relays unless you get a lot more information, because if there are only 2 wires to each motor then it is using reversing polarity which means that something is connected at all times. At least, see what the lock (violet/black) and unlock (Brown.black) will do. And hopefully there was some sort of instruction book came with it.
 

Thread Starter

chris4817

Joined Dec 30, 2019
5
I see that the module does have lock and unlock inputs, so use them and don't mess with additional external relays unless you get a lot more information, because if there are only 2 wires to each motor then it is using reversing polarity which means that something is connected at all times. At least, see what the lock (violet/black) and unlock (Brown.black) will do. And hopefully there was some sort of instruction book came with it.
That was my thought as well. However The violet black (lock) is connected to battery positive and the brown black(unlock) is connected to ground.
 
I can;t make much sense out of that "wiring diagram". They mention 200 mA which usually isn;t enough to drive a lock motor The TS is mentioning 2 wires yet I see BOSH style automotive relays. So, confused.

I also don't know it you have the lock motors in parallel or the voltage drops.

So, let's pretend I know VERY LITTLE. 2 wires with little or no voltage drop, Maybe 200 mA.
This website: https://www.parts-express.com/12-vdc-bosch-type-dual-relay-socket-for-door-lock-unlock-circuits--330-078 and the application notes.

A "possible" datasheet: https://www.mouser.com/datasheet/2/418/NG_DS_V23234-X0000-A001_1118-124805.pdf

75 ohm coil. 12/75 mA = 160 mA; pretty hefty. Enough to drive a relay, but not a motor.

back to pretending you have two wires. The parts-express has an application note that has both positive and negative trigger door lock circuits.

OK! back to two wires. 200 mA.

You can create a negative trigger door lock circuit and lets say, two relays; lock and unlock. You can also put two relays in each door. So, two relays, wired as lock/unlock with BOTH motors connected as the output,

So, ground or +12 to activate, pick one and wire accordingly.

Now, put a bridge rectifier on the "2-wires" from the alarm module's "2-wires".

Put a diode in series with the lock relay and the unlock relay. Make the polarities different.

Or use something like this: https://www.amazon.com/ELECTRONICS-SALON-Passive-Channel-SPST-NO-Module/dp/B00UA4DW5Q You probably don;t need or want an active circuit. Depends.

So, you'll have one polarity activate one relay and another polarity activating another because of the series diode.
Put a 1n4001 diode across the coil to absorb the spike when the relay turns off.

So now you have relays that can connect to the final Lock and Unlock relays and can be ground or +12 activated and are low current, So, you connect a low current rated (enough to handle the bosch relay) push button across the lock or unlock contact.

e.g. +12 to the center of a (ON)-off-(ON) switch that does the same as the lock/unlock signal. remember if loc and unlock are on at the same time, nothing happens.

It's not the best and not the smallest circuit. The bridge, messes up ground. You don;t want the circuit powered at all times.

So, the quick description is:

Use a bridge rectifier and stering diodes to create an isolated contact closure for lock and unlock. Use these contact closures to
provide +12 signals to the main lock/unlock BOSCH relays that activate the motors. Put momentary switch/switches such that they "parallel" the isolated contact closures. Isolated means isolated from the lock motor so you can have a GND or +12 referenced lock and unlock signal.

Two separate lock/unlock Bosch relays mounted in the door is another option.

What's causing confusion is the signal naming by the alarm module manufacturer, no schematic or equivalent circuit of the alarm module.

Bosch relays in the picture and "2-wires" don't make any sense. Lock and unlock "contact closures" to ground via transistors makes sense. A connection to +12 that isn't needed except it's the return path for the suppression diodes makes sense too. Search for a UL2003 datasheet.
 

MisterBill2

Joined Jan 23, 2018
5,753
That was my thought as well. However The violet black (lock) is connected to battery positive and the brown black(unlock) is connected to ground.
I see my error now, which is that the other input is the violet wire. And since they are bot labeled as INPUTs, normally open, it seems that a switch to momentarily ground either one or the other should deliver either a lock output or an unlock output. So it appears to me that these are the lock and unlock button inputs that are asked about in post #1. What is a lot less clear is why they are tagged as 87 and 87A, since those are usually relay contact designations.
I suggest using a voltmeter to see what voltage is on these two wires while the module is powered.
Is it installed in the car already? Or is the Chris hoping to find an answer prior to staring the installation?
 
I see my error now, which is that the other input is the violet wire. And since they are bot labeled as INPUTs, normally open, it seems that a switch to momentarily ground either one or the other should deliver either a lock output or an unlock output.
Thought that too, BUT violet and violet/black are permanently onnected to +12 in pic #2. It does make it an "input",just not in an I/O sense.

85 and 86 are the coil and those pins are not visible. If it's inside the alarm, there whould be a dotted box around it.
 

MisterBill2

Joined Jan 23, 2018
5,753
Thought that too, BUT violet and violet/black are permanently onnected to +12 in pic #2. It does make it an "input",just not in an I/O sense.

85 and 86 are the coil and those pins are not visible. If it's inside the alarm, there whould be a dotted box around it.
I see that and that part of the "screen shot" makes no sense at all. It does not show any way of driving that lock motor in more than one direction. So where did that drawing come from, as it does not seem to relate at all to the other drawing? It is well drawn but it does not seem to make any sense at all.
So we need to get some information from the TS. That second drawing just does not make any sense at all.
 

Thread Starter

chris4817

Joined Dec 30, 2019
5
The actuators have only 2 wires. From my understanding, there are two relays inside the unit that fire based on lock or unlock. My only possible thought is that maybe the mounting bracket Inside the door provides a 3rd, “ground” connection. Like I said, I am new to this stuff, so I apologize if I can’t give the information needed. I was only given the two diagrams originally attached to work with...
 

bwilliams60

Joined Nov 18, 2012
1,282
I think the alarm module is controlling the relay coil for lock and unlock. If I am correct, pin 30 goes to one side of the actuator. Pin 30 from the other relay goes to the other side of the actuator. Four actuators are connected in parallel. Battery power goes in through pin 87(NO) of each relay and ground goes in through pin 87a(NC) of each relay. When one relay coil is activated, it uses the second relay in its at rest state. I think you need to open up the box and see where you can grab control of the coil input or ground. Not sure which side they are switching on.
 

MisterBill2

Joined Jan 23, 2018
5,753
The keyless entry installed, and is it connected to an alarm module?
Does setting the alarm lock the car, or does locking the car set the alarm? And is there an option offered for having the alarm separate from the keyless entry module? Presently it appears that the second drawing is a poor attempt at describing the interface part of the keyless entry module, and it seems that the "input" connections are the feeds for the lock and unlock relays. so please verify that the lock/unlock motors have the blue and green wires feeding them. It is not a case of the ground being the third connection, but rather that at rest both sides of the motor are grounded, , while to run the motor one of the sides is switched to supply 12 volts to the motor to run it. And after quite a dit of study it does not seem that there is any intentional way to have a manual lock or unlock function switch in the car. It could be added with two more relays, one for lock and one for unlock, but where would you mount them? They would each have the common running to one side of the lock motor, the NC (87a) side connected to the module output, and the normally open side (87) connected to the fused +12 volt line. One relay willlock, the other will unlock. You would need two burrons, one to power each relay coil. If there is a simpler way they have done a good job of hiding it.
So I am waiting for an answer, although it is getting late on New Year Day, and I did ring in the new year last night.
 
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