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EXT idle project

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I have been reading about the EXT idle and how to wire it on here. Lots of threads but Ralph77's postings are what got me going. He made it work and look stock on his dash. I am not concerned with it looking that way, all I want is it to work.I figure it would cost me over a hundred dollars acquiring the parts on Ebay or elsewhere. If the correct parts find me then maybe. Instead I am going to use a simple toggle switch and place it in a hole I already have on my dash. There was once a problematic alarm system I disabled long ago but there is still a little red indicator light installed next to the gauge cluster and I can use that for the hole. First problem was locating and verifying the solid grey A-12 wire that is in the PCM harness connector #1. I opted to open the large wiring harness closer to the brake booster for room to grab the grey wire easily. You must be careful because there are several grey wires in that harness. Some have various tiny colored stripes and are hard to see. Then there is another solid grey wire that you MUST NOT get confused and cut. It is from the same connector #1 and position #7. By opening the wire harness where I did I was able to grab the grey wires and pull while looking to see if the A-12 wire at the connector moved. Once I verified the A-12 only then did I slice away a bit of the insulation to test it. I ran a wire with an alligator clip to a good ground and then touched the bare end to the A-12 grey wire while the engine was running. The idle jumped right up to 1000rpm. You guys were correct about that. Then I scrounged a length of double wire with a protective sleeve and cut what I needed from that. The ends I soldered to the grey A-12 wire and a black ground wire. The ground I attached with a ring terminal under one of the sheet metal screws that secures the PCM mounting bracket. Once I have sealed and shrink-wrapped the connections the rest of the wire can be fed through the fire wall through a grommeted hole someone already made for the alarm wiring. Then I can get a small toggle switch and solder the wires to that. For now I am sealing my solder connections with Liquid Electric tape. That is a neoprene sealing liquid I use on all my auto and boating wiring. It dries semi-hard and waterproof. Then shrink-wrap and electrical tape. Here I am so far:

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Discussion Starter · #22 ·
Thanks Ralph. But you are the one that got me started on this. Much obliged. I have to drive the Wife to Jury Duty this month so I will use the XJ and see if anything occurs. Keeping fingers crossed.
 

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Discussion Starter · #23 ·
UPDATE: I have good news and bad news. The good news is that the idle does indeed sit at 1000rpm in Park, Neutral, and Drive, etc. The bad news is that it releases at the slightest movement of the vehicle. I am guessing the PCM over-rides the EXT idle command when the electronic speedometer detects movement. Or perhaps one of the other transmission sensors. But when you come to a complete stop, the idle does go back up to 1000rpm. So if you don't need the EXT idle while actually driving it is fine. If you are stopped dead in traffic with the AC, lights, etc, on then it will bump it up until you move. To have the idle stay up while driving I guess you will need to fabricate a mechanical throttle stop solenoid like they used on AC and anti-dieseling applications. It would need to be adjustable so you can set the idle where you want it and be able to engage it at the flip of a switch. Oh well, I still like the system I have as I can warm the engine up faster as well as sit in traffic at a higher idle.
 

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Does anyone have the actual schematic for the circuit? Not looking for a home drawn one, but an actual Jeep/Chrysler schematic from the manual.

EDIT: I'm actually searching for the details on the internal switch circuitry, not for a wiring diagram. Seems like it is a highly guarded secret :)
 

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Sorry for resurrecting an old post, but I knew that after three days of searching, I'd find it the moment I posted the question.

Page 8W 30-17

cdn.xjjeeps dot com/pdf/en-us/2000-service-manual.pdf
Now I totally misunderstood you.
I thought you wanted to see what the "circuit board" looked like in the switch,
So all you did want is a wiring diagram.
Unless I am misunderstanding you now.
What each wire in a Ext Idle pigtail does is well documented on the internet.
 

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Now I totally misunderstood you.
I thought you wanted to see what the "circuit board" looked like in the switch,
So all you did want is a wiring diagram.
Unless I am misunderstanding you now.
What each wire in a Ext Idle pigtail does is well documented on the internet.
You are correct. Ultimately, I do want to get my hands on a real switch to see the circuit board. I was able to confirm some things with that page in the FSM, but I'd still like to see what the circuit board looks like to remove all doubt, hopefully without paying $300-$350 for one of the three currently available on eBay.
 

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You are correct. Ultimately, I do want to get my hands on a real switch to see the circuit board. I was able to confirm some things with that page in the FSM, but I'd still like to see what the circuit board looks like to remove all doubt, hopefully without paying $300-$350 for one of the three currently available on eBay.
I will show you one but only if you tell me how jealous you are of my Ext Idle switch. LOL
 

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Insanely jealous. Because you have a factory switch AND bezel....and I don't. :). But I'm not $299 jealous.

Yet....
Well I am going to let you in on a little secret.
But you can't tell anybody. LOL.
While that is a Mopar 4 slot bezel it is not an American one.
See XJ's in the UK and over there in Europe have rear fog lights.
Like it is a law or something over there.
Well when they have fog lights and rear fog lights in an XJ guess how many switches are in the bezel?
You guessed it.
4.
So I sourced a 4 slot bezel from over there. Came with the all the switches.
Now it is not a perfect solution. The fog light switch goes in the slot third from the left.
The rear fog light switch is in the 4th position.
See switches have these keyways on the side of them that correspond to slots in the bezel.
Keeps them from putting a switch in the wrong position.
So both the Ext Idle switch and the fog light switch wanted to go in the 3rd position.
Not wanting to mess with the Ext Idle switch I ground the keyway off the fog light switch.
Also so you know a fog light pigtail can be used with an Ext Idle switch.
You just need to grind off the keyway on the pigtail and instead of hooking it up by wire color you use wire position.
I also had an idea for the rear fog light switch that came with the bezel.
See I put an overhead console in my '00 that did not come with one.
This guy 3D prints this 4 slot bezel that goes in the garage door opener area.
Uses factory switches.
So I want to put some lights up front, some in the rear, and maybe some more down the road.
So I thought using a rear fog light switch for the rear lights would be cool.
Notice how the symbol is reversed.
But a rear fog light switch acts different then a fog light switch. It is not just an on/off but kinda spring loaded like a rear wiper switch.
So I used the toggle part only and the rest is a regular fog light switch.
Now this project is not done. Still need to wire up an aux fuse box and find a central location for my relays.
I did buy the lights I am using up front but not the rear ones yet.
Only mocked things up and did some prep work so far.
 

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Well I am going to let you in on a little secret.
But you can't tell anybody. LOL.
While that is a Mopar 4 slot bezel it is not an American one.
See XJ's in the UK and over there in Europe have rear fog lights.
Like it is a law or something over there.
Well when they have fog lights and rear fog lights in an XJ guess how many switches are in the bezel?
You guessed it.
4.
So I sourced a 4 slot bezel from over there. Came with the all the switches.
Now it is not a perfect solution. The fog light switch goes in the slot third from the left.
The rear fog light switch is in the 4th position.
See switches have these keyways on the side of them that correspond to slots in the bezel.
Keeps them from putting a switch in the wrong position.
So both the Ext Idle switch and the fog light switch wanted to go in the 3rd position.
Not wanting to mess with the Ext Idle switch I ground the keyway off the fog light switch.
Also so you know a fog light pigtail can be used with an Ext Idle switch.
You just need to grind off the keyway on the pigtail and instead of hooking it up by wire color you use wire position.
I also had an idea for the rear fog light switch that came with the bezel.
See I put an overhead console in my '00 that did not come with one.
This guy 3D prints this 4 slot bezel that goes in the garage door opener area.
Uses factory switches.
So I want to put some lights up front, some in the rear, and maybe some more down the road.
So I thought using a rear fog light switch for the rear lights would be cool.
Notice how the symbol is reversed.
But a rear fog light switch acts different then a fog light switch. It is not just an on/off but kinda spring loaded like a rear wiper switch.
So I used the toggle part only and the rest is a regular fog light switch.
Now this project is not done. Still need to wire up an aux fuse box and find a central location for my relays.
I did buy the lights I am using up front but not the rear ones yet.
Only mocked things up and did some prep work so far.
Nicely done! I've had my eye on the eBay for stuff from the UK too, I'm in search of the elusive 4 bay bezel but I might go for a 3d printed one and add more switches.
Nice find on the reverse fog switch, I will most likely do the same or source the toggles from an eBay aftermarket source. RockAuto has cheaper prices on factory and Standard switches than dealer or Amazon.

PM me with the source of your 3d printed overhead bezel, that's nice, I've ben considering adding that for the additional lighting I have planned for the XJ.

I can't post pictures on here with the img tag yet, so you'd just have to cruise on over to our web site to see the XJ at takeatripwith dot us/our-equipment.
 

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PM me with the source of your 3d printed overhead bezel, that's nice, I've ben considering adding that for the additional lighting I have planned for the XJ.
There was this guy on another forum I am on who made them and you could buy them through shapeways.com.
He has not been active for quite sometime over there but his stuff can still be bought.
I think he might have been the first to come up with 3D printed bezels for XJ's.
You see them everywhere now but I don't really remember seeing any before he started talking about them on the forum.
Here is all his work:

https://www.shapeways.com/shops/gctent

And here is that bezel I bought.

https://www.shapeways.com/product/L...-garage-door-panel?optionId=63515302&li=shops

Not cheap but I really wanted it cause it kinda looked factory and it goes in the garage door opener section of the overhead which is useless to me.
I think he might make this same bezel that will take those contura switches too.
 

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There was this guy on another forum I am on who made them and you could buy them through shapeways.com.
He has not been active for quite sometime over there but his stuff can still be bought.
I think he might have been the first to come up with 3D printed bezels for XJ's.
I thought I recognized it. If found him a couple of weeks ago when I first started down the EXT Idle path. There are a couple others out there doing 3D printing of these, but I agree these seem to look the most like stock with the pebble grain finish.

I didn't mean to hijack the thread, but then again, a lot of good information has been added to it so it may not necessarily equate to hijacking :)
 

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Discussion Starter · #40 ·
Not a high-jack at all. This is all about adding the feature and making it look stock. I used an ugly toggle switch on my '00 but I was able to use the three hole bezel on our '01. But on the '01 it only works in P or N. On the '00 it works in D also. An update: the rpm drops when moving in gear, but not unlike it does anyway in gear. I expected it to stay at 1000rpm, but the drag of the transmission eats up a couple of hundred rpms. The computer tries to maintain the 1000 rpm but cannot. It is still better than the 500 or so rpm it drops to with out the EXT engaged.
 
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