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How To: Power To Accessory Circuit After Key Off

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Old 04-01-2005
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How To: Power To Accessory Circuit After Key Off

Note: This is an unauthorized mod that I did to my 2003 Ranger for my own reasons. I present it here for informational purposes only. If you choose to do something similar, you do so at your own risk.

This is a simple mod that will provide power to the accessory circuit (including radio, power windows & wipers / washers) after the ignition switch has been turned off. The accessory circuit will remain powered until the driver's door is opened. As pictured below, it should work on 2001~2003 Rangers and possibly earlier years as well. The 2004+ Ranger is a different beast electrically and this will not work as written for 2004-on.

It requires 2 standard Bosch pattern SPDT relays which are available at the Ford dealer for about $7 each - a good one to use is a replacement for a Ranger's heater blower motor relay. It is easy to connect wires to the relay pins using quality 1/4" insulated spade terminals or special relay sockets.

All wires are readily accessible in the radio cavity with the radio removed. It may make things easier if the radio bezel is also removed.


NOTES:

***There are two yellow/black's in the drawing: one to the GEM and one to the HU. They have different functions and must not be interchanged nor connected together.

***The GEM module has two connectors. The yellow/black (yellow wire with a black stripe) to be tapped for the door open signal is in the connector closest to the front of the truck. CAUTION: There is also a black/yellow (black wire with a yellow stripe) in the same connector - be careful not to mix them up.

***I used 16 gauge wire throughout to match the truck wiring. The spade connectors and wire taps used should also match the 16 gauge wire.

***Pin 30 of the relay on the right side of the diagram should be tapped to the Black/Light Green wire of the dash harness going to the head unit. There are two of these Black/Light Green wires and the larger one should be used.
 

Last edited by RazorsEDGE; 11-15-2011 at 12:09 PM.
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Old 04-02-2005
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Originally Posted by loneFX4
got one for auto up and down windows of both driver and passenger side windows?
I refer you to Mr. Griggs's excellent how-to:
http://www.cardomain.com/memberpage/296394/22
 
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Old 04-02-2005
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Originally Posted by shadyluke
My 2000 has a time delay for the windows as do other trucks I'm sure. I think I am gonna have to do this one so I can have the radio too. Excellent job Bob!!!!
The 2001+ no longer have the time delay for the windows.

I'm not sure this transfers directly to 2000-back. There may be different color codes or other adjustments needed.
 
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Old 04-04-2005
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Originally Posted by NHBubba
Doh! Teach me to go shopping w/o instructions!

I found automotive relays at Radio Smack, but didn't realize they were SPST and not SPDT! So I have no pin 87a! Anyone know where I can get SPDT relays for cheap locally. I'm presuming the dealership is going to bend me over, like anything else. Bob, surely you have a cheaper source, no?

Also would you mind describing what the wires we're connecting to are? I don't have a wiring diagram.
The cheapest place for the relays is an electronics house $3~4. You can get generic SPDT relays at Radio Shaft or an auto parts place for $5~10+.

I like to use the genuine Ford relays from the dealer - they are heavy duty relays designed for a 40A, continuous duty circuit. Just ask for the relay for the HVAC blower motor. My dealer gets $7 for them.

Green/Purple is hot at all times
Black/Light Green is chassis ground in the radio harness
Left side Black/Yellow is hot in RUN or ACC in the radio harness
Right side Black/Yellow is switched to ground through the driver's door switch when the door is open

All it does is latch the hot to the accessory wire on key up and use the door trigger to break the latch.
 
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Old 02-26-2006
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I attempted this MOD but failed. I got power to the windows but not the radio but than the power didn't cut off, ever. Will I be UNABLE to do this mod considering I did the no door chime where I have to take the same GEM Wire and tap it into the Grey/Red Wire? I hooked everything properly but still no go. This is a small mod that would make a big difference for me. It must be differenct for 2000s cause when everyone is describin the wire colors and what their uses are, mine are different. Mine didn't come with power windows or power anywhere includin the engine so I don;'t have that 10 second delay thing.
 
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Old 02-26-2006
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The color codes involved here don't appear to have changed from 2000 to 2001. Things are a bit different because you teed the yellow/black door driver switch to the passenger side input to the GEM (gray/red).

You might be able to make it work by teeing the wire (shown as YE/BK) at the right side of the diagram to the gray/red going to the GEM. The accessory wire should go dead when either door is opened.
 
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Old 02-26-2006
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Well I thought I got it done properly when I first did it cause the windows began working but than all of a sudden I noticed my key wasn't even in the ignition so I was like aw crap. But just to make everything super clear So I know Im hooking everything up properly.... the relay on the right that the black/green wire is coming into, do I need to make it so I cut the black/green wire and reconnect them but with a third one going to terminal 30?
 
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Old 02-26-2006
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All 4 wires get teed into the truck wires as indicated in the diagram. You don't need to cut anything in the truck if you use scotch-loks.
 
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Old 02-26-2006
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All, this modification will be attempted next weekend after my stress levels have subsided and alll my school work is finished, heh. Thanks for the replys.
 
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Old 02-27-2006
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Alright, I did it and I used a wire tap for all of them and even though I have the dinger mod thing, I connected the wire tap to the grey/red one and its working perfect. Thanks for the creator of this great mod! Thanks.
 
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Old 02-27-2006
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Good job!
 
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Old 02-27-2006
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so does the power not work to those units after the door is opened? or will you always have power to those after the key is turned off?
 
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Old 02-27-2006
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Originally Posted by zabeard
so does the power not work to those units after the door is opened? or will you always have power to those after the key is turned off?
Power is maintained to the ACC circuit after key off until the driver's door is opened. Or, in his case, until either door is opened.
 
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Old 02-27-2006
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sweet, that is what i thought. i need to get me some relays now. lol

thanks Bob!
 
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Old 02-27-2006
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This is a fantastic mod, probably one of my favorites in my truck. I'd strongly recommend buying some of those relay base pigtails (the ones that lock together) and affixing the "structure" to a structural member inside the dash with 3M tape. At first I used some blade connectors, wrapped it all in electrical tape, and basically shoved it into the dash... and what happens when some of those connectors get loose can be maddening. (I spent about half a day smacking my dashboard to turn the radio back on until I got home to take the bezel out.)
 
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Old 02-27-2006
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Yeah, I mounted it with 3m Double Sided tape as far back as I possibly could. I like this soooo much. I put in power windows while ago and a lot of times they will still be down when I turn off the engine cause Im not thinking about it but no longer do I have to put the key back in the ignition, just push the up and shabam. Its also good casue I have an MP3 player that I have hooked up to my radio and a lot of times Ill park and sit there and listen to it until it shuts off completely and stops sending the signal while the engine is still runnning so now... I might save about 5 cents of gas per tank :)
 
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Old 02-27-2006
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I just remembered something. There was a minor incompatibility between this mod and another one. IIRC, it had to do with the autolamp/autodim mirror - like if you turned off the ignition with the lights on and didn't open the door, the autolamp feature would not turn the lights off for you until after the driver door was opened. I believe that was it.

There should be an easy fix for it and one that I've been meaning to do anyway. The way the mirror is wired in the How-To, the autolamps are activated in both the ACC and the RUN modes of the ignition switch. This is a nuisance if you turn the radio on at night with the key at ACC (engine off) because it turns on the lights, too. Sure, you could reach up and turn off the autolamps feature manually at the mirror but that pretty much defeats the purpose of having the headlights automatically controlled.

Anyway, I am going to move the keyed mirror power from the Yellow/Black wire of the radio wire harness (Hot in RUN and ACC) to the Red/Yellow wire (hot in RUN and START) like the Explorers were wired from the factory.

The Red/Yellow is available at several places around the dash but I think i will pick it up right at the headlight switch. The wire to tap is the THINNER 22ga Red/Yellow at the H/L switch. (The THICKER 16ga Red/Yellow at the H/L switch is the power out for the headights and it is switched by one of the relays added in the AL/AD mirror mod. Tapping that one will not work.)

That simple change should clear up both the incompatibilty problem and the "headlights on in ACC" problem..
 
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Old 02-27-2006
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Aw. I see. I don't think I am going to change the way it is now out of pure laziness but thanks for the follow up.
 
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Old 02-27-2006
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A relay is just an electromechanical switch. A common automotive type is the Bosch pattern relay with pins laid out like this


When the coil gets power and ground at 2 pins (85 and 86), the coil is energized and the relay switches.

There is a common connection for the switched contacts at pin 30

pin 87 is normally open to pin 30 (closes when the coil is energized)

pin 87A is normally closed to pin 30 (opens when the coil is energized)




Coil not energized (default/rest position):




Coil energized:
 

Last edited by V8 Level II; 02-27-2006 at 08:22 PM.
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Old 02-28-2006
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Originally Posted by Gearhead61
So basically when there is no current running through pins 85 and 86, the current runs from pin 30 to pin 87, but when you run a current to 85 and 86, the current on the other path changes from 30-87 to 30-87a, right?
It is the opposite.

0 volts across the coil -> continuity from 30 to 87A
12v across the coil -> continuity from 30 to 87
 
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Old 03-01-2006
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If you do this mod, you can play your radio without the key in the ignition:
-Close the driver door and open the passenger door.
-Turn the ignition key on and then off and remove the key (this latches the relay circuit).
-Turn on the radio and enjoy. The radio will continue to play until the driver door is opened.




On the flipside....a word of caution:

After doing this mod, your accessory circuit always remains hot after keying off until the next time you open the driver door. I forgot about this once and found my battery dead the next day.

Here's how it happened: one evening, I went out to my truck and opened the passenger side door. I got in, reached across from the passenger seat and keyed on the ignition to check something, turned the ignition off again, then closed and locked the passenger door and went inside. What I hadn't noticed was that the radio was powered on but the volume was turned all the way down.

Without realizing it, this series of actions had latched the relay circuit, keeping the accessory circuit hot. The amp drained the battery long before morning. Hopefully, this won't happen to you!
 
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Old 03-10-2010
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Originally Posted by 99greenranger
Does anyone know if this will work on a 1999. This is a feature I had on my last car and was bummed that I did not have it on my truck.
I don't have a 99 here to test it on but the schematics seem to say that it should work. The only apparent difference from the instructions is that the 95~2000 GEM has up to 4 plugs instead of the 2 on the 2001~2003 Rangers. For 95~2000, the yellow/black door switch wire should be in the largest of the 4 plugs (26-pin).
 
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Old 04-14-2010
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Originally Posted by mikerider
So bob anyway to add a timer in to this circuit as a fail safe? My explorer times out after 15 minutes after the key has been turned off. any ideas?
Your Ranger has a "Battery Saver" circuit that shuts off power to the courtesy lights after roughly 10 minutes. There should be a way to use that feature to make a time out disable for this mod.
 
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Old 02-10-2012
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Does anyone know or have the wiring diagrams to share for the 2011?
I would love all if possible but specifically for this mod as "it is a different beast"
I would love to have an accessory delay, kinda bugs me not having one.
thanks
 
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Old 04-14-2013
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Originally Posted by putput
Does anyone know or have the wiring diagrams to share for the 2011?
I would love all if possible but specifically for this mod as "it is a different beast"
I would love to have an accessory delay, kinda bugs me not having one.
thanks
I'm attempting this mod on my 2011 XLT . I've found all the necessary wires except the ground whenever the door opens. I've checked every yellow and black wire within sight, and I've checked a good amount of others with no luck. One source said green with purple, but no luck there either. Anyone know what color it is or where I can locate the door's ground trigger?
 

Last edited by sasquatch35; 04-14-2013 at 09:24 PM.

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