Hey guys, real quick. Have fully functioning OD in my 1995 Dakota v6. Just having a problem with the SWITCH itself. Sometimes it works, sometimes it doesn’t. I have to 5ton push it and even then it might not engage.

How exactly do I install a toggle switch? I was reading that on the OD plug on the transmission has 2 wires, 1 hot and 1 that the ECM uses to control the ground.

So can I just install a toggle switch somewhere and run 1 wire to the ground wire at the OD Plug and the other wire to a ground on the chassis?

 

Umm ...

Might be better to bypass the OD switch module. As I Understand It, the module pulses a high to the ECM to turn it on, or off. It might pulse a ground to it.

And *ahem* There's no ground wire at the OD/LU plug (and it's a 3 pin connector on your 1995!)

Before you start doing too much, check the FAQ. There's a link to the 1995 Factory Service Manual download; and it's got all the wiring diagrams in it.

I'd grab that FIRST.

And study it up carefully.

Might be better to fix the lockout switch in the dash.

RwP

 

O/D Off button just sends a return signal to the PCM to change state. (from on to off, or off to on, depending on what it currently is.) Likely its just the button itself that's the issue. I think you can find them on ebay, or amazon. (new and used....)

 

Thanks for your input! I was looking through the Service Manual and it says the PCM operates the OD solenoid by way of grounding it via pin 55 at the PCM. So, theoretically, if i install a toggle switch tied in to that specific pin, and run it to ground, it’ll work. Off to find pin 55.

I’m going through all this trouble because F the original switch that’s why.

 

Erm, what do you want the switch to do? If you ground that wire, it will engage the solenoid. If you simply break the circuit with a switch, the PCM will set a code when it tries to enable O/D, and nothing happens.

Fix the factory switch if you want to disable O/D.

 

Disconnect the factory switch and you'll keep OD available.

What's the reason why you're trying to screw up the ECU?

RwP

 

When I start the truck the OD is automatically off and I have to fight the switch to get it to kick on. I live a few minutes off the highway and am using the truck currently to commute about 30 miles one way and on occasion way more.

Wait, I read somewhere that a guy kept the switch unplugged and had OD all the time. I didn’t get to try it yet but that’s exactly what I would like to accomplish.

Gonna try this out. Thank you guys so much!

 

Sounds like a bad switch...... I might be tempted to check and see if a previous owner didn't do something odd, to have the system default to off. That is not the way it came from the factory.

 

HeyYou is right - the default is OD; the switch is to DISABLE OD on demand.

Looking at page 8W-30-3 in the FSM, it says that you pulse pin 10, the orange/white wire, to 12V to disable / enable OD. If you pull the OD switch, you can either leave it disconnected for 100% OD available, or add a push button to toggle it.

Shucks, take some contact cleaner, squirt it through the switch, and see if you can get it to start working better.

Now - one thing to note. If I'm not mistaken, the light ON is OD OFF. And the light OFF is OD ON. (Hopefully one of the other posters with a 4speed can correct this if I'm wrong.)

RwP

 

That is correct for the operation of the switch.

But, isn't the switch powered FROM the pcm as well as sending the return signal (when you push the button) back to the PCM? (that's the way it works on the full sized trucks, no idea on the older, smaller stuff.)