4PL 3 Position Momentary Switch Mod

[YJ_Driver]

The most likely cause is wiring the transistor wrong as different models will have differing pinout. Re-check the E B and C pin locations on the particular transistor you're using.

If this doesn't fix it let me know the part number for your transistor and I'll have a look at the datasheet.

[Shoe]

Does anyone know if I can get these parts at Radio Shack and what the part numbers would be. Thanks

[Crank]

Originally Posted by Shoe

Does anyone know if I can get these parts at Radio Shack and what the part numbers would be. Thanks

Yes.
All of the parts needed are on the wiring diagram on the first post.
Transistor is a MPSA92
4.7k 1/4 watt resistors

Just be careful electronics like this aren't as forgiving of mistakes as something like a motor.

[nsimps]

I did this mod a long time ago and the radio is still working amazing. Love having a momentary switch to use for winch control. I would have a hard time going to anything else.

Thanks for the great write up!

[xj96jeep]

Hi, I am having trouble with this mod. I did it to my 4pls, and can only get dt4 to work one way and not the other. Any ideas?

Thanks,
Mike

[joshsmith512]

My 4pls is the same way, even redid the mod 3 times, always the same outcome. I just use it for momentary in as in is all you really need.

[xj96jeep]

I'm guessing there is something a little different in the circuitry between the 4pl and 4pls. I plan to mess with it a little more if I figure something out I will let you know. If not one direction will work fine for me as well.

[xj96jeep]

Joshsmith512 I was able to get my momentary switch to work as a 3pos on my 4pls. On my 4pls I was able to just run jumper wires from DT4 straight to SW2. It is very similar to YJ_Driver's schematic and uses 3 of the same solder points. Here's a generic
schematic.


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[southernfourbyfour]

So for the 4PLS we don't need the parts at all just jumper wires? Also momentary can be good for dig application on a comp crawler

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[xj96jeep]

Originally Posted by southernfourbyfour

So for the 4PLS we don't need the parts at all just jumper wires? Also momentary can be good for dig application on a comp crawler

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Yes this is correct. Mine has been working flawlessly since I posted the schematic.


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[southernfourbyfour]

Awesome. Looks like it's time to break into my remote. Warranty is up finally

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[xj96jeep]

Originally Posted by southernfourbyfour

Awesome. Looks like it's time to break into my remote. Warranty is up finally

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Did you have any luck?


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[southernfourbyfour]

Haven't done it yet. They bought out the 4pv and I've been trying to figure out if it's got a momentary

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[joshsmith512]

Dude xj96jeep i just stumbled across your post, time to dig in and get this working right. Thanks for the info

[xj96jeep]

Originally Posted by joshsmith512

Dude xj96jeep i just stumbled across your post, time to dig in and get this working right. Thanks for the info

No problem! Let me know how it works for you. Mine has been going solid.


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[joshsmith512]

Score bench tested work great.

[Chiphead]

Got to bring this one up from the dead...


I am not seeing a pic referenced in post #28 by xj96jeep. Can anyone help with this? I am hesitant to dig in. It can't hurt to ask if anyone has a schematic or concise instructions before I do.





I have a Futaba 4PLS. Using the adjustable drag brake on an RX4 is a pain in the arse with the Futaba. It will be ideal to have a momentary switch.

[HumboldtEF]

Originally Posted by Chiphead

Got to bring this one up from the dead...


I am not seeing a pic referenced in post #28 by xj96jeep. Can anyone help with this? I am hesitant to dig in. It can't hurt to ask if anyone has a schematic or concise instructions before I do.





I have a Futaba 4PLS. Using the adjustable drag brake on an RX4 is a pain in the arse with the Futaba. It will be ideal to have a momentary switch.

You can still see it if you use the photobucked embed fix plugin.
EDIT: actually I dont know why I can see it and you cant.

But I grabbed the pic and re-hosted it so it will hopefully stick around for a while.

[Chiphead]

Thank you!!

I ordered up some transistors (I already have the resistors) and will get this soldered up. Looking forward to using the momentary switch for the Mamba Drag Brake function and winch controls on other models.