electronic trunk release
Printed From: the12volt.com
Forum Name: Car Security and Convenience
Forum Discription: Car Alarms, Keyless Entries, Remote Starters, Immobilizer Bypasses, Sensors, Door Locks, Window Modules, Heated Mirrors, Heated Seats, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=133269
Printed Date: July 05, 2025 at 5:43 AM
Topic: electronic trunk release
Posted By: rdgfx32003
Subject: electronic trunk release
Date Posted: January 11, 2013 at 2:37 AM
I'm installing an electric trunk release in a 1993 Toyota MR2. The vehicle has a Car-Pro CPX-3600 alarm. I've had the solenoid for a few years. I just never installed it. It's a universal kit and all
I have is the solenoid and the mount.
I've mounted the solenoid where I want it but I'm not clear on whether I'll need a relay or how I should wire this up. The only information I have is from the Car-Pro CPX-3600 installation manual and all it states is that the blue wire from the 9 pin mini connector wire harness is for the negative input for a trunk release.
What do I need to know to make this work? Thanks.
Replies:
Posted By: kreg357
Date Posted: January 11, 2013 at 5:52 AM
Most add-on trunk release kits come with wiring and a push button switch. The solenoid should
have two terminals / wires coming off of it. One will connect to chassis ground and the other will
supply it with a +12V when the solenoid is to be actuated ( trunk popped ). This +12V lead is usually
fused at 10 Amps. Your CPX-360 Trunk Release output is a low current negative pulse that is designed
to control a relay. Obtain a 30/40 Amp SPDT relay with harness and wire as follows :
Relay Pin 85 to CPX-360 Trunk Release Output
Relay Pin 86 and Pin 87 to +12V fused at 10 Amps
Relay Pin 30 to positive lead of trunk release solenoid.
Additionally ( IHOH ), please add a quenching diode ( 1N4007 ) across Relay pins 85 and 86 with the
band towards pin 86.
The negative lead of trunk release solenoid is connected to a solid chassis ground. ------------- Soldering is fun!
Posted By: KPierson
Date Posted: January 11, 2013 at 8:26 AM
I'm not familiar with that line of alarms but make sure it is a trunk release OUTPUT not a trunk release INPUT that you are connecting.
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Kevin Pierson
Posted By: rdgfx32003
Date Posted: January 12, 2013 at 10:04 AM
kreg357 wrote:
Most add-on trunk release kits come with wiring and a push button switch. ...
Relay Pin 30 to positive lead of trunk release solenoid.
Additionally ( IHOH ), please add a quenching diode ( 1N4007 ) across Relay pins 85 and 86 with the
band towards pin 86.
The negative lead of trunk release solenoid is connected to a solid chassis ground.
Thanks, that's what I needed. But what is (IHOH)?
Posted By: kreg357
Date Posted: January 12, 2013 at 3:05 PM
IHOH = In Honor of Howie II 
A seasoned forum member that always reminds us to protect the systems with proper diode usage and placement. ------------- Soldering is fun!
Posted By: rdgfx32003
Date Posted: January 13, 2013 at 12:37 PM
Aha. IHOH.
This drew my attention.
KPierson wrote:
I'm not familiar with that line of alarms but make sure it is a trunk release OUTPUT not a trunk release INPUT that you are connecting.
On further inspection, it turns out it is a negative input.
kreg357 provided me with guidance for a trunk release output type.
Relay Pin 85 to CPX-360 Trunk Release Output
Relay Pin 86 and Pin 87 to +12V fused at 10 Amps
Relay Pin 30 to positive lead of trunk release solenoid.
Additionally ( IHOH ), please add a quenching diode ( 1N4007 ) across Relay pins 85 and 86 with the
band towards pin 86.
Posted By: rdgfx32003
Date Posted: January 13, 2013 at 12:44 PM
Oops I posted before I was through, sorry.
My last post was going to finish up with a request for info for negative input wiring.
On the installation sheet it's described as: Trunk Trigger (-)input.
Posted By: rdgfx32003
Date Posted: January 13, 2013 at 1:09 PM
I'm going to revise again.
The kit came with the wiring and a push button switch. Those items are lost and all I have is the actuator and mount. The actuator isn't marked which side is positive, but I don't think it will hurt it to get it wrong the first time. It will either be released or unreleased and I can switch the wires on the actuator if it's wrong, I guess.
I downloaded the installation manual for the CPX-3600 a few days ago and now I can't find it online for ####! I find the operations manual but not installation.Good thing I already downloaded it.Stumps me as to where I found it before.
Posted By: kreg357
Date Posted: January 13, 2013 at 3:14 PM
As Kevin pointed out, there is a difference between a Trunk Release Output and a Trunk Trigger Input.
The Trunk Release output is to pop the trunk. A Trunk Trigger input is for the CPX-3600 to detect when
the trunk is open. The relay described earlier is to be used with the Trunk Release Output, the relay
and actuator solenoid. If your CPX-3600 is an alarm system and has a separate Trunk Trigger Input wire
you would connect that to the MR2's trunk trigger wire. Typically, if the vehicle came with a factory alarm
system, there should be a trunk pin somewhere. Here is the wire info from Ready Remote :
Trunk/Hatch Pin RED / Green (-) @ theft ECU It is a (-) signal, so a direct connection is OK, no relay
required. An alternative trunk trigger signal would be the trunk light, if equipped. I don't see any wire
listed, so use a DMM to test & verify.
-------------
Soldering is fun!
Posted By: rdgfx32003
Date Posted: January 14, 2013 at 7:17 AM
I took the liberty of uploading the CPX-3600 installation manual and the operation manual to the12volt.
I did some research on the car and found out it did not come with a factory installed alarm.
I'm not sure how to proceed now, since there was no factory alarm.I don't know where to pick up an output signal. Another reason I uploaded the docs was for some kind individual to examine the install sheet and hopefully prevent me from burning down the car. :-)
Posted By: kreg357
Date Posted: January 14, 2013 at 8:03 AM
Thanks for the manual uploads. Interesting unit. It is an alarm system with keyless entry.
It appears that the Gray 2nd Channel Output wire is your Trunk Release Output, but I can't be sure from the limited info in the guide. That wire would be connected to the relay mentioned above.
If your car does not have a trunk pin, you can always install your own and connect to the Blue Trunk Trigger Input wire. ------------- Soldering is fun!
Posted By: rdgfx32003
Date Posted: January 14, 2013 at 12:36 PM
Thanks. I'll proceed per your instructions. 
Incidently, there is a wire off of the trunk latch and the key switch mechanism.(two seperate locations and different color wires) One of those operates the light in the trunk. I could use that for the Blue Trunk Trigger Input wire if the polarity is correct. Would that connect directly to the blue wire regardless of polarity. (I'm pretty sure no. Of course the polarity would make a difference.)
I verified the wire off of the trunk latch mechanism is a single wire that operates the trunk light. How would I determine polarity of that wire with my DMM?
I'm not sure of the other two that come off of the key switch mechanism, yet.
Posted By: rdgfx32003
Date Posted: January 14, 2013 at 4:09 PM
It turns out the other two wires went to the factory alarm.
If you're still out there, is there anything electronic I may have laying around broken (lots of broken electronics here) that I can rob the diode out of?
Posted By: kreg357
Date Posted: January 14, 2013 at 7:06 PM
Most Printed Circuit Boards have diodes but you need a blocking diode ( not a zener, etc ). You can check the printed marking on the diode for 1N4007 or 1N4004. If you find them, delicately de-solder them and then check them with a DMM. Here is a link : https://www.ehow.com/how_7378447_test-diode-rectifier.html
The easy way, would be to go to RadioShack and get a 3 or 5 pack of 1N4004's for about $2. ------------- Soldering is fun!
Posted By: rdgfx32003
Date Posted: January 18, 2013 at 8:28 AM
I didn't want to go to the Shack,really. I went ahead and went though.
Thanks for your help.
Posted By: howie ll
Date Posted: January 19, 2013 at 8:31 AM
All the trigger wires in the Toyota are NEG.
Do you have a SECURITY LED on your instrument panel?
If so you have a factory alarm and its location on Japanese and UK models was right rear quarter behind the door.
Doors, front and rear storage areas and engine bay all have triggers.
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
Posted By: rdgfx32003
Date Posted: January 19, 2013 at 5:27 PM
Hi howie II,
The factory alarm is not present. The Mr2 has had the Car Pro alarm since I've owned it.
All the factory alarm wiring is present, which makes it easier.
Thanks for checking out the post, every suggestion is appreciated.
Posted By: howie ll
Date Posted: January 19, 2013 at 5:49 PM
Then the switch (trigger) wires from the front and I think rear cargo areas and the doors all go to that location.
The engine bay is quite easy to mount a switch, go through the right there's a massive grommet in the bulkhead, left r/hand rear carpet on the other side and you're through.
P.S. I also mount the siren on that model there, can't be got at and better sound, also I then mount the alarm module and right front seat. Don't worry about long cable runs, the wiring at the ignition switch is thin gauge, esp. the starter wire.
-------------
Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.
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