High idle installed…finally!

I searched high and low for a way to make my truck idle up. Why? When jump starting another vehicle, using the winch, or my power inverter I wanted the alternator to turn faster to keep up with the voltage demand. I thought about a twist lock throttle cable, but wanted more options. I finally just completely fabricated a system that works pretty damn good. In the dash I used another ECT switch from the salvage yard. It’s illuminated at night just as the ECT switch is. I cleaned the ECT label off of the switch and installed a “high Idle” switch label. I wanted an indicator light as well, and since the ECT indicator is in the instrument cluster, I decided to look there for a light that was not being used on my truck. I found an open, no label slot where the indicator is located in the dash. I cut a hole in the coolant temperature gauge face, then placed the same switch label in the instrument cluster. I then colored the label with a sharpie so it cannot be seen unless the light is on, matching the rest of the cluster. I’ve been running a black instrument cluster for as long as I can remember, I didn’t like the white face gauges. Under the hood I used a throttle stop/high Idle solenoid from Napa. Holley makes the exact same solenoid for twice the price. I fabricated a sheet metal bracket and found a nut that the solenoid would thread into. Welded it all together and painted it before installing. The solenoid is not strong enough to lift the throttle, but locks into the full extended position once reached. I guess that’s why they call it a throttle stop. Anyway, I have it wired through a relay, it grounds through the body of the solenoid, so only one wire has to be connected to the solenoid. I wanted some safety defaults in place, and the primary side of the relay is where I installed them. Three things have to happen before it activates. #1 push the high Idle button, this sends power to the indicator light and the coil of the relay. #2 The red parking brake light has to be on, this grounds the primary coil of the relay, this can be accomplished by pulling the parking brake one click, just enough to turn the light on, or full pull park brake application, depending on the situation you may not want to have the brake applied, like winching out of a hole. #3 finally tap the throttle with your foot, this allows the solenoid to come to the end of its stroke and lock into place. The throttle plate is now being held open by the solenoid. It’s also adjustable, as the brass bolt in the solenoid is just that, a bolt to adjust your idle to whatever RPM you like. I have mine set to 1800 RPM now. I decided not to go with any type of neutral safety, as winching in gear is possible, and the fact that the last step is actually tapping the throttle pedal.


The high Idle is not engaged at this time, I simply started the truck to get rid of the other dash lights that are on KOEO.


What do you guys think? Total cost, less than $100.00, along with a pretty big headache. I also wired my factory differential lock indicator to come on in the instrument cluster when either air locker is engaged.

 

Very cool! Ive thought about doing something similar on my truck, primarily for use during winching. Unfortunately 2nd gens or newer kind of complicate things.

But for 1st gens this looks about as clean as it gets. Well done.

 

You could have got the same alt voltage from one of those Australian fuses that puts out 14.5 at idle. Clean install though.

 

That only boosts voltage.

 

I have an upgraded alternator, two batteries in parallel, no isolator. My voltage at idle is 14.3~14.5 with no load. I have a warn 8k winch, plus a lot of lights, but most are LED. My biggest current draw is the winch by far. If you use the winch, the truck will actually lose rpm because of the demand on the alternator, but that also depends on how much weight I am pulling.

 

I thought about this post again today at work. I was working on a 2016 Ford F-350 with a 6.2L gasoline engine with a check engine light. I deleted my post from yesterday because I wasn’t sure if you could do this with a scan tool on a gasoline truck, turns out you can. I mostly deal with Diesel engines at work. Anyway, I went to output state control and there was the Desired Idle option. Clicked on it and could increase the idle in 100rpm increments up to 1700 rpm. So my post from yesterday mentioned a plug and play device through the OBDII connector to have a fast idle. The technology is there, getting a company to produce it at an affordable price is a whole different subject. But you are correct about it complicating things, any input that doesn’t come from an expected place on the network is going to turn the CEL on.

On the other hand, I measured how far my solenoid moves my throttle. Just a little over 0.100” small increment for such a high idle. The old school cable idea would have been a nightmare, attaching it at the throttle body anyway, the pedal maybe a different ratio.
All things considered, a fast idle can be complicated on anything, as it can’t interfere with normal throttle operation at any time.

 

Have you noticed a difference in the accessory performance with the extra ~250 RPM at high idle?

 

When my truck is at normal operating temp it idles around 800 rpm. So this high Idle adds 1000rpm. But to answer your question, I’ve not tried to winch anything, or tested anything. I know that before installing this system, when I have the A/C on high, and all of my lights burning all at once, every accessory on, the voltage drops slightly. I could rev the engine up and the voltage would increase, that’s the whole reason why I installed this kit. Theoretically it should work, but I have not tested it. I’ve just finished the install, so I can’t really answer your question just yet. I chose 1800 rpm because that is my rpm at 55mph.

 

This is the solenoid I used, if anyone is interested. The brass bolt is a 1/2” hex. I had to trim it down to a 1/4” square for throttle linkage clearance.

 

That is badass man. Got any pictures of your truck? Sounds like a sweet build.

 

They are coming soon, my truck looks nothing like the pics I have on my profile. I’m planning on making a build thread at some point.
Thanks for the compliment.

 

Interesting, dont think I saw that post you are talking about. At any rate Im sure it could be done through the OBDII somehow. But in my mind the tricky part about that is making sure its 'safe', aka making damn sure the system only turns on when the driver wants it to.

For as little as this system will ever get used, the red neck in me says just wrap a dowel in velcro and stick it to the trans tunnel so it pushes on the pedal

 

Most of the vehicles that I work on have high Idle functions. That’s where I got the idea. Most of them are diesels with a PTO. The PTO is the main reason for the high idle, but some of the older Fords have a charge protect function. The more electrical load you put on it, the faster the rpm will go. All that has to be set for this function to activate is the truck has to be in park or neutral, engine running, and press the parking brake.
On the heavier vehicles, like a tractor trailer, you simply use the cruise control buttons to set the desired idle rpm.

 

Great work, very clean.

 

This is pretty cool. Nice clean install.

 

I love the fully thought-through problem solving here. Very nice work!
Wild guess: you'd be a great neighbor to have.....

 

I'm stealing this! With a winch and onboard air, I cant believe I haven't thought of this. Clean install!

 

Someone didn't read the fucking thread.

 

Very cool. Will look into doing this myself.

 

Honestly I’m not familiar with the product that you suggested. It may have been a solution for the problem I was having. I’m not sure. I just know that the winch pulls a lot of amps, the faster the alternator is spinning, the more amps it’s capable of. Voltage and amps are very different, and I wasn’t fully clear about that in my original post, and I did use the word “voltage”. Most of my amps are drawn from the batteries, then slowly replenished by the alternator. Like I said in an earlier post, I have already upgraded my alternator to the 105 amp bolt in replacement, but the engine rpm would still drop when I activate the winch, and you can clearly hear the alternator whine.