What does the Trans Kick down solenoid do?

If opt for the one called out. 24V will kill the civilian one (12V) in time. They aren't engaged much, but still.
The H1, from 1991 (I think) on, uses the 4L80E, different kettle of fish.

The TH400 uses a vacuum modulator (in gas applications) to set shift points and shift firmness, AND a kick down switch to force a downshift at speeds below maximum 2nd gear governor speed.

Milcommoguy said:

Kick down or cable pull. What's the cable pull from the injector to the side of the transmission for? Maybe kick down?

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This is an older thread I resurrected, so I’ll assume you’re asking me.
Its a kick down solenoid type of connection for sure, only a single wire connection to the drivers side of the trans, mid way back. I’ve checked the circuit and the wire seems good and the switch works so I suspect the solenoid itself. I should add my HMMWV is a 1987 6.2L with 3L80 trans
Bulldogger

Same behavior on my HMMWV. Will follow TSB to test-adjust kickdown switch.


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erasedhammer said:

Another one of am generals mislabeled harness's?

I have my fan timer disconnected so my fan is on all the time. Does this affect how the kick down solenoid works?

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Ehammer, why are you driving with your fan running all the time??? Sucks the life out of already underpowered truck... Just wondering.. If you like to hear things roar... lol

Maybe resurrecting this thread will cause some new information to come available. I purchased the kickdown switch [correction Solenoid] from Hummerpartsurplus and am expecting it Monday. I intend to replace it Friday when I've taken the day off (5th).

I've been putting it off. The switch [correction Solenoid] isn't expensive, but dropping the pan to get at it was never high on my list of things to do.

Bulldogger

The switch isn't in the pan. The solenoid is in the transmission.

https://hummerhuren.files.wordpress.com/2013/01/hmmwv_test-diagnostics.pdf

The switch> chapter 6 page 8
The transmission> chapter 6 page 7

The modulator control cable adjustment also very important for proper shifting, so chapter 6 is a good one.

Before getting all oiled up, do the checks. In my box of tricks... A 4 foot flexible wire with small alligator clips and VOM are the electrical tools of choice.



Easy test, Clip lead to transmission solenoid contact point and ground measure resistance 60-70 ohms, GOOD. Unsure, Start truck, same clip lead at transmission. Get er rolling. Apply 24 volts to solenoid at will to force a down shift. 3rd to 2nd or 2nd to 1st doesn't matter, unless transmission is a mess. Keep the wire out of the way of hot or spinning parts.

Engine off, Ohm meter to switch leads, peddle to the metal "almost". Should read less than 1 ohm. If linkage and floor mats and dirt clods and bad switch equal issues.

Best friends in my tool box for electrical tests or hot wire to GO, CAMO

If it is the solenoid, easy swap and good time to PM filter, oil, an eyeball inspection & button it up.

My mistake in terms. I bought the solenoid. My switch tested good last time I checked it. Process of elimination caused me to suspect the solenoid.
Am I correct in remembering the solenoid is accessed by dropping the pan?

Bulldogger

You are correct.