pac tr7 & dei 535t

Overview: I have installed this combination in my 2014 Tacoma to allow me to control all four windows using my Factory Keyless Entry. 1 DEI 535 for the Front Windows in 2-window mode, another for the Rear.

I have two PAC TR7, one tied to the 12V positive when driver door locks, programmed to look for 2 pulses in five seconds and then latch ground on the output wire for five seconds. This output is tied to the 'ground when armed' wire on the DEI 535Ts to roll up all four windows.
(LOCK TWICE CAUSES WINDOWS TO GO UP)

The second PAC TR7 is tied to the 12V positive when driver door unlocks, programmed to look for 3 pulses in five seconds and then latch ground on the output wire for five seconds. This output is tied to the 'auxiliary input' on the DEI 535Ts' to roll down all four windows.
(UNLOCK THREE CAUSES WINDOWS TO GO DOWN)

Problem: Occasionally the Roll Down function does not work.

After some troubleshooting, it appears sometimes there is just enough voltage being detected on the "ground" side of the motor during the unlock operation to trigger the first TR7(LOCK) which disables the roll down features and in fact, triggers a roll up.

Questions:
Can I use a resistor between the locking 12V on the door lock and the TR7 to reduce that voltage? If so, what value would I be going for? The TR7 is sensitve to as little as .8V so I need to get it below that.

Is there something else to consider? Other options? Are the TR7 just no good for this? No good period? I've considered using a relay to break the connection between the 12V LOCK and the TR7 during unlock but this feels like overkill.

If I cannot solve this, the solution will be to remove one of the TR7 and choose a direction to automate.

Thanks in advance!!!!!
-Rob

I'm wondering if you are actually triggering the "up" TR7 before triggering the "down" TR7. Door lock actuators can be rather noisy, electronically and it's possible that the TR7 on the "lock" side is occasionally picking up signals from the "unlock" operation.

Have you tried recreating the problem with the windows half way down? If my theory is correct when the windows are supposed to go down, but don't, they will go all the way up.

I'm not familiar with the circuity on the TR7 but have worked with some other door lock hardware and it worked best with a very high resistance inline with a transistor. I would assume the TR7 has a transistorized input but I have no idea what kind of inline resistor there is. You can play around and I would start with around 1 meg.

Also, you mentioned something about the "ground" side of the motor. I would not reference the motor for ground at all. I am not sure if that was a mistake or if you actually meant it. The ground should be grounded to a solid ground point and the + input should go the "LOCK" and "UNLOCK" wires respectively.

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Kevin Pierson

Aloha,

Thanks for your reply. Some responses in line.

KPierson wrote:

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I'm wondering if you are actually triggering the "up" TR7 before triggering the "down" TR7. Door lock actuators can be rather noisy, electronically and it's possible that the TR7 on the "lock" side is occasionally picking up signals from the "unlock" operation.

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This is exactly what is happening, I didn't do a good job explaining it.

KPierson wrote:

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You can play around and I would start with around 1 meg.   

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I assume this is one megohm ?   

KPierson wrote:

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Also, you mentioned something about the "ground" side of the motor. I would not reference the motor for ground at all. I am not sure if that was a mistake or if you actually meant it. The ground should be grounded to a solid ground point and the + input should go the "LOCK" and "UNLOCK" wires respectively.

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Not a mistake. I am using the two wires going to the motor as my trigger for each TR7. There for the (+) wire for lock becomes the (-) wire for an unlock operation. My meter shows some small voltage off the (-) wire during each operation. This is triggering the lock operation.

Hope that makes sense and thanks again.

And, No, i am not using the ground of the motor for my circuit. All the grounds are running to a dedicated location behind the kick panel. Thanks!

An electrician friend of mind suggested using a 100 Ohm Ceramic resistor inline between the motor lock (+) and the TR7. I actually had one lying around and so far, it seems to have worked. The resistor did not affect the reading on my voltmeter, but according to my friend, it reduces "noise" on the circuit that may have caused the false triggers on the TR7.

Thanks,
Rob

Nope. That didn't last. Still seeking recommendations

Why not use 2 relays- one for lock, one for unlock?

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My ex once told me I have a perfect face for radio.

100 ohms isn't enough, like I said try a 1 meg (1 megaohm, 1,000,000 ohms) resistor. The high resistance will filter out most, if not all, of the noise and only allow the high voltages to trigger.

When using a transistorized input circuit to detect door lock pulses I used to use a 10K resistor. However, sometimes noise would cause undesirable operation. I am currently using 1.5meg and haven't had any issues with noise since I made the switch.

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Kevin Pierson

Thanks again for your suggestions. So yes, 100 ohm was not enough. We had a 5000 ohm resistor lying around and that has cured the missed roll down symptom but sometimes it wont roll up. I suspect 5K is too much resistance. Not to contradict your suggestion but I cant see 1 Megaohm being better but i'm not expert.

I still think 2 relays (with flyback diodes installed) would do the trick.

Connect one relay's coil terminal (85/86) to the wire that goes positive on lock, and ground the remaining coil terminal. Don't forget to install the flyback diode across the coil. Now connect terminal 30 to a fused 12 volts, and terminal 87 to the lock input of your TR7.

Do the same for the unlock wire.

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My ex once told me I have a perfect face for radio.

geepherder wrote:

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I still think 2 relays (with flyback diodes installed) would do the trick.

Connect one relay's coil terminal (85/86) to the wire that goes positive on lock, and ground the remaining coil terminal. Don't forget to install the flyback diode across the coil. Now connect terminal 30 to a fused 12 volts, and terminal 87 to the lock input of your TR7.

Do the same for the unlock wire.

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Thanks, didn't mean to ignore your suggestion was just trying avoid adding more wiring to the door. ;). Thanks again!

No problem. Let us know if this works for you.

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My ex once told me I have a perfect face for radio.

darobman wrote:

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Thanks again for your suggestions. So yes, 100 ohm was not enough. We had a 5000 ohm resistor lying around and that has cured the missed roll down symptom but sometimes it wont roll up. I suspect 5K is too much resistance. Not to contradict your suggestion but I cant see 1 Megaohm being better but i'm not expert.

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Without knowing how the PAC is configured it's impossible to say. I would, assume, though that it has a transistorized input. It may already have a high amount of resistance on the board.

I find it odd that 5k seemed to work for one but caused issues for the other. I would keep playing around with different values until you find something that works for both.

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Kevin Pierson

KPierson wrote:

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I find it odd that 5k seemed to work for one but caused issues for the other. I would keep playing around with different values until you find something that works for both.

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It's not all that weird.

Here is a crude wiring diagram.


The original problem was that during an UNLOCK operation, the TR7 LOCK was seeing some voltage/current/noise on the then grounded terminal of the lock solenoid. Adding the 5K resistor, filtered this voltage/current/noise so now the TR7 LOCK is no longer seeing this current during an unlock operation and does not activate the DEI 535Ts.

What I think is happening now is the 5K resistor is filtering a bit too much, so that when a normal lock operation occurs and there are 12V+ on the line connected to the TR7 LOCK, it is filtered a bit too much and the TR7 does not see the pulses. Hope this helps explain it.

For now, I'm happy with the operation. If it becomes more troublesome, I'll probably remove the TR7 LOCK device. I installed the DEI units to add One-Touch functionality which works perfectly. Secondarily, I wanted the ability to trigger a roll down with the factory keyfob to cool the vehicle down. Rolling Up was just icing on the cake.

Thanks Everyone!

Here's the diagram