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rear defogger auto on with remote start

Printed From: the12volt.com
Forum Name: Relays
Forum Discription: Relay Diagrams, SPDT Relays, SPST Relays, DPDT Relays, Latching Relays, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=119983
Printed Date: May 03, 2024 at 4:30 AM


Topic: rear defogger auto on with remote start

Posted By: sniperess
Subject: rear defogger auto on with remote start
Date Posted: February 08, 2010 at 5:07 PM

Hey all,

So I want to have my rear defogger turn on when I remote start the car, or at least wire it to AUX 1 so I can just push the button the my remote :)

I had the starter installed at a shop and I don't have a wire diagram for my car, so I'm not too sure how to wire AUX to trigger the rear defogger. As such, I assumed I could wire a relay to simulate a button push.

I could push a button (as part of my climate controls) to turn on the rear defogger. It will only turn on if the engine is running and the car will not automatically turn it on (even if left on when turning car off).

I took everything apart and attached two wires to the momentary button switch, when I short these two wires it simulates the button push, and hence turn on/off the rear defogger. This is what I tried doing with a relay, but it doesn't seem to work.

85: +12v, same wire I'm using for "remote" on my amp. It's powered with ignition is ACC or ON.
86: -12v @250mA output from Remote Starter
30: one wire of momentary button switch
87: other wire of momentary button switch

posted_image

I started the car and pushed AUX on my remote but it didn't seem to work.

Is this relay setup correct? Is there a way I can test this without wiring it to the car to energize the coil.

Alternatively, I believe I could just use the AUX to pulse on a factory wire and it will turn on the rear defogger. If someone could tell me which wire that would make this easier I guess.

2009 Mitsubishi Lancer 2.0L
CompuStar CM5200 with 2-way remote

Thanks.



Replies:

Posted By: smokeman1
Date Posted: February 08, 2010 at 8:32 PM

I don't know what kind of car you have but I also wanted my rear window defroster to come on with the remote start. Hope this link can get you started in the right direction.  Lots of excellent help for these guys.

https://www.the12volt.com/installbay/forum_posts.asp~TID~118680





Posted By: sniperess
Date Posted: February 09, 2010 at 5:54 AM
I have a

2009 Mitsubishi Lancer

with

CompuStar CM5200 remote alarm/starter

I don't have a proper wiring diagram so I don't know which will trigger rear defogger :(




Posted By: yimke
Date Posted: February 09, 2010 at 9:33 AM
Just pay them to do it it costs at most $40. You will void your warranty with them if you try it yourself, and possibly might break something.

Otherwise if you don't believe me, your rear DEFROSTER will only work if they powered up the correct accessory wire in the vehicle that powers the switch.

You basically have to get behind where the switch is located and meter the wires going into it. It should either read:

12volts then when you push it and drops to 0v and stays there. This is called a (-) latching defroster.

12volts then when you push it drops to 0v then jumps back to 12volts. This is called a (-) pulsed defroster.

0volts then when you press it jumps to 12volts. This is a + latched defroster and requires a relay to switch polarity and increase your amperes.

Make sense? Tell us what you are metering and we can advise you on what to connect. But if it was me and didn't have a bad experience with the shop I would just pay them. Because if you go back to them for any OTHER issues and they see what you did, then they will make you pay EVERY time you have to come back. Depends on the policy of course though.




Posted By: dereileak
Date Posted: February 15, 2010 at 9:09 PM
I just found my rear defroster wire right at the harness where it hooks up to the controls, and then took my wire that came with my viper 5902 that gives out a 200ma negative, hooked it up, cause my wire showed 12 volts when off, and when on went to like 1 volt, but this wire causes it to go to ground and turns on the relay

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Viper 5902 - Ordered
Kicker Dual CVX 15's - Installed
Kicker ZX 1500.1 Amp - Installed




Posted By: t&t tech
Date Posted: February 16, 2010 at 11:45 AM

dereileak wrote:

I just found my rear defroster wire right at the harness where it hooks up to the controls, and then took my wire that came with my viper 5902 that gives out a 200ma negative, hooked it up, cause my wire showed 12 volts when off, and when on went to like 1 volt, but this wire causes it to go to ground and turns on the relay

I'm assuming this is in a 2009 lancer! Otherwise it would have no relavance to this thread, so....................., could you post the colour wire and where you found it! I'm sure the OP would appreciate it!



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COMMIT YOUR WAY TO JEHOVAH AND HE WILL ACT IN YOUR BEHALF. PSALMS 37:5




Posted By: howie ll
Date Posted: February 17, 2010 at 7:42 AM
Of course there's plan "B" but before I tell you what it is you must realise Yimke has given you the right advice. Frankly if a security system came back to me with ANY problems and I find the car owner or their "mate" the plumber who fits "car stereos" in his/her spare time had touched the system in any way, it's immediately "good-by warrantee" and the clock's running.
Having said that take a meter and find the wire at the rear that goes to 12V+ when you activate the HRW. Ascertain the colour then verify it at the front, probably driver's kick panel.
Take an aux from your CM2500 and programme it for timed, 15 mins.
Connect to 85 on relay.
From your ignition switch, acc wire, feed 86 and 87. Cut the wire you found, originally and join the switch end to 87a, the other end to 30. Incidentally people coming in on other peoples posts are silly because it causes bad feelings, confusion and things don't get answered!
There I've finally answered a post that begins with "SO". My normal inclination is to say "So effing what?"




Posted By: yimke
Date Posted: February 17, 2010 at 8:53 AM
You don't need a relay for this wire. Just hook it up and program your defrost for latching. Usually is preset for 10 minutes.





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