Simple Unintrusive High Idle Circuit

[89Laredo]

What you need:
(2) 3 Amp Diode (EX: Radioshack 276-1144)
(1) 3/8 Female Spade Connector
(1) 3/8 Male Spade Connector
14 GA Wire
(4) Butt Connectors
Solder (preferred over butt connectors)
Soldering Iron (if using solder instead of crimp connections)
Heat shrink or Electrical Tape

Diagram:

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This will allow you to add a high idle switch to your truck without cutting up your stock harness.

Gather your materials:

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Add your Male spade to one end of the wire. The male spade will later connect to the engine harness (original high idle circuit). Crimp or solder. Heat shrink if you have it, or electrical tape.

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Cut about two inches of wire and add your Diode. The BLACK end (NOT the stripe!) should face your Male connector you just added. This should preferably be a solder connection but use butt connectors if you must. Heat shrink or electrical tape when you are done.

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Cut another two inch chunk, ALSO grab your remaining wire. Push BOTH of these wires into the female spade and attach (crimp or solder). Heatshrink or tape. The short piece is for the harness you are making, long piece goes into the cab and to your switch.

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Now attach the piece you just made and the other with the diode. Should end up with something that looks like this. (But hopefully prettier, this was a quick hack job)

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Now go out to your truck and connect to the existing wiring. Tie the wiring out of the way when you are done.

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You can test for function by touching the long wire to your positive battery post. You should hear the idle solenoid click and hold the throttle open just like it normally does on a cold start. You should NOT hear the advance solenoid click. The end connecting to the stock harness should have no back feed at all, you should be able to touch it to ground and have nothing happen.

Run wire into cab, connect to switched +12V, and you are done.

High idle will work as it should on a cold start, and now you have the option to run it whenever you want without turning the cold advance on.

 

[franklin2]

You may hear the solenoid click, but most of these solenoids are not strong enough to push the throttle open, they will hold it up though, so you usually have to "help" it with a slight push of the pedal with your foot. You probably already know this but I am not sure everyone does. This is probably part of the reason why the starting instructions on the sunvisor tell you to hold the throttle open some when you are starting the engine.

 

[junk]

Very nice write up. And very simple.

 

[BDCarrillo]

Very nice, simple, and effective! I nominate this for transfer to the Tech section.

 

[snicklas]

Agreed, off you go......

 

[Dsl_Dog_Treat]

Duplicate to this one.
http://www.oilburners.net/forums/showthread.php?10326-High-Idle-Solenoid-Manual-Control

 

[snicklas]

Sorry Ron, forgot about that one. I will move this one back and open it back up for discussion.

 

[89Laredo]

Not exactly the same...

 

[IDIoit]

im kind of worried about that diode.
those things are flimsy!
how do you recommend strengthening this area?
seems like if you tug on it the wrong way, it would break?
maybe shrink wrap?
any other suggestions?

THANK YOU SNICKLAS FOR RE-OPENING IT FOR ME.

 

[Dieselcrawler]

in rons writeup, he did cover it all with heatshrink. I always cut the ends down as short as I can to eliminate the risk of breaking them, then cover in a thick heat shrink

 

[franklin2]

im kind of worried about that diode.
those things are flimsy!
how do you recommend strengthening this area?
seems like if you tug on it the wrong way, it would break?
maybe shrink wrap?
any other suggestions?

THANK YOU SNICKLAS FOR RE-OPENING IT FOR ME.

In the picture below, I would move the diode over against the other red wire and wrap the diode to to the other wire with electrical tape and put both of them in a split loom. That should hold it.

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[89Laredo]

It really should all be soldered and heatshrink, like I mentioned in the writeup. I didn't have any around, was a quick midnight project.
I think a couple layers of shrink on each side of the diode, then one bigger one over the diode and the leads would make it pretty stiff. Or just large amounts of tape like I did. Lol

I changed it after that pic and cut the wires quite a bit shorter.

 

[89Laredo]

Changed the diagram but havent gotten around to rewriting steps /taking pics. Added a diode so you dont get 12v running to your cab switch when the stock temp switch turns the high idle/advance on.

 

[Agnem]

You can seal up the diode and wiring in FIT 321 or equivalent heat shrink. It has a glue inside that melts and makes the assembly strong. This is a good mod, and I've had one in the Moose Truck for years. I also added a circuit that powers a blue indicator light on my dash when the circuit is getting power through the cold temp switch, and I also routed the solenoid power through a switch, so I have three positions... no high idle/automatic/high idle and can choose what I want.

 

[KZF250]

I read in another thread where Gary tells how to adjust the plunger to set the High Idle, but I'm curious if there are two different stops that the plunger remembers??? On my visor it says to depress pedal 1/2 way if it's a certain degrees and all the way if it's colder...What's the difference???

Next project for me is to add two manual switches...one for Fast Idle and one for the Timing Advance so that I can use one or the other or both as needed. Thoughts on that? Neither one seems to be working at the moment and hoping it's not the solenoids, just dirty contacts or faulty Temp Sensor.