So I, not being to smart I might add, bought this:

https://www.ebay.com/itm/262933259151

I did not have much faith in my being pleased with this but my curiosity got the better of me. It comes with a pig tail too. See the first shot. Well I was not. There is an on light but no light for the symbol. Plus the pig tail only has three wires and looking at this write up I see four.

https://www.cherokeeforum.com/f51/ho...switch-204925/

So having extra fog light switches lying around I decided to see if I could use the part that says EXT IDLE with everything else from a fog switch. There is a translucent part that I believe the light will show through to light up the words EXT IDLE. See the second shot where I circled. Now that is a fog light part but very similar to the EXT IDLE. I already put it together before I took a pic.

To get it to fit all together I had to make a slight adjustment to the fog light switch case. There are 2 little nubs on each side of the actual switch. See the third shot. One fits one does not. So I took a small philips screwdriver and kind reamed the hole a bit. See the fourth shot.

So I was able to get it back together and the switch appears to operate. At some point I will plug it in to my fog lights and see for sure. Also to see it the words EXT IDLE lit up with the headlights on.

So this is the part I wonder about. Wiring them up. I put factory fog lights in my '00 that did not come with them. There is 4 wires in the connector for the fog lights. Also even if a '97 up XJ did not come with fog lights the connector and the wires are behind the blank. So getting a connector with wires will be easy.

So from installing the fog lights I know the following:

Black is ground
Purple is for the 12V run source for the switch
Blue will be the 12 volt out to the relay
Orange is the illumination for the switch.
Not the on light but the symbol when you turn on the headlights.

Thinking I could translate the above to what thatXJguy wrote in his write up:

1. An orange wire (this controls the lighting and dimming)
2. A black wire (this is a ground)
3. A blue and white wire (this is where an ignition power source needs to go)
4. A gray wire (this needs to be routed to pin A12 on your computer)

I know there is a flaw somewhere here. Just don't know where. Need you guys to let me know what you think.

So I don't even know why I did this. I do not need an EXT IDLE. The first thing I want to do is plug the switch into my fog lights just to see if it works, could have put it back together wrong, and to see if the words EXT IDLE will light up with the headlights on.

The last shot is the instructions they sent with the switch.

 

So I went and tried the switch with my fog lights. It worked so I put it back together correctly. Also the words EXT IDLE lit up with the headlights on. So I was right in my thinking that it would show through the translucent material I saw on the inside. Now how bright it will be at night is unknown cause I checked during the daytime.

 

What is (an) "ext idle"?

 

Its usually found on police package Xj.. Kicks the idle of the motor up. It would be used if you are sitting at idle and have all your lights, police gear running or using a winch draining alot of power.. You would hit this switch to get a little more RPMs out of the motor. I think it puts the motor at 1500rpm..In turn the alt starts to charge the batt and help with some of the load.

 

I thought it was a 1000 RPM but I could be wrong.

So stupid me finally figured out what a couple people were trying to tell me. I think. The Ebay Ext Idle switch is not a real Ext Idle switch. It is really just an on/off switch. To maybe make it more clear it is a fog light switch with an the words Ext Idle on it. Which explains why the guts and circuit board looked the same to me. Now it appears using a relay can still make this work. wizardpc in post # 14 at the link for the write up above posted what to wire to where when using a relay.

So I want the words Ext Idle to light up with the headlights on. I am thinking I could just tap into one of the wires on one of the other 3 switches (rear defog, rear wiper, or fog lights) with something like this. Think it would be OK?

 

You are probably right at it being 1000..
I just took a guess. thats why I said I think..

 

I wasn't sure either and Googled it after I posted that. Appears it is 1K RPM. I don't even know why I am doing this. Guessing the off season has gotten me that bored. LOL.

 

Yep that will do it..lol

 

Know what else it does? It brings up your oil pressure while idling and helps keep the engine cooler because the fan is turning faster. Same concept that Detroit used on their diesel engines for years because oil pressure would drop down and they had trouble cooling themselves at normal idle. These tend to do that when it's hot also. Almost every Detroit has a "fast idle" switch.

 

I thought the high idle switch on the Detroit rigs was for letting the motor warm up faster on cold starts. Also something about helping keep the heat up when sitting idle on cold days.

First time I heard about the cooling thing,,hmm interesting.

 

All kinda makes sense when you think about. RPM is higher, water pump is turning a little faster, gotta figure coolant is circulating a little faster. Might even apply to the alternator maybe.

 

Im in Alaska,, We don't need to worry about cooling stuff off. So most of the stuff I have heard is about heat.. But yes I can see how cooling would also being a thing..

 

Yep, cooling was an issue in hot weather, they would sit there and make themselves even hotter if more air wasn't pulled through the radiator. And once the engine was up to operating temp and the oil was hot they would drop pretty low in pressure, apparently too low for comfort according to the engineers. So idling it up helped on both accounts. But in marine applications the cooling was not an issue, just the oil pressure.

The difference and reason they created and maintained more heat like this and ran lower oil pressure compared to other engines was because they are two stroke engines.

 

I think we discussed this at length here awhile back, but I want to set up an extended idle system that works like a cruise control, or kind of like the old "hand throttles" Jeeps and most 4x4's used to have. Here's why... Out here in the desert when the temp is over a hundred degrees and you are idling along over rough stuff in first low for miles on end they really need a slight boost in RPM to keep it cool.

It is a pain and huge effort to try and maintain this little but needed difference with the foot feed for 5 miles or more in first low. I think I have it figured out so that it can be done safely and shut it's self off when the brake is applied just like the cruise does, but I am still not sure what latching relay to use. I need some advice from someone who has more knowledge on electronics than I do.

The real trick would be to eliminate the "minimum speed" for cruise control application. But I couldn't get anyone here to even discuss the possiblity of this option. lol

 

I always assumed that too, which is why I really don't know why I am thinking about putting one in, but I think I read somewhere that it only operates in Park or Neutral. And can not be used with a manual transmission. But it would not surprise me if I read it wrong.