What plugs are necessary to make the swap work on the transmission? I have the 3.4 out of a 97 4runner with an auto transmission and its sitting in my 1992 4runner manual transmission. I see lots of plugs on the 3.4 harness but are any of them necessary? I'm guessing one of them is for a speed sensor, is that correct? I have manual hubs and disconnected the ADD system so I know I don't have to connect the transfer case but I would still like to. Is it as simple as cutting of one connector and putting on the old one from the 3.0 harness and if so which connector do I cut off to replace? The donor I got already had the transmission removed so I'm at a loss for some of the connections.

Thanks

 

From the little I know about the wiring on this swap so far assuming I understand correctly, you are going to have to trick your new 3.4 Auto ECU in some way. I believe most people source a manual ECU so they dont have to deal with the headache of trying to jump through the hoops required. You are definitely not going to have the connectors/wires that the ECU wants to see in your truck related to the auto transmission that is no longer there.

 

Not sure about the 92, but for my 91 4Runner's swap there were 2 connections from the 3.0 engine harness that needed to be cut off and grafted onto my donor 97 4Runner (also auto) engine harness: R (for reverse), and the 4x4 indicator switch (closed when in 4H/4L, open when in 2H).

You'll need the reverse signal for your backup lights to work, and you'll need the 4x4 indicator for the 4WD light on your dash to work (you'll need to do a little more work to fake the ADD indicator as closed, but not much).

 

That was what I was looking for. Just not sure where to graft the two connection to in the mess of connectors I don't need off of the auto harness.

 

Yeah I have converted the auto harness to manual and have the correct manual computer to make it all work.

 

For the reverse light circuit:
From the EWD navigate to "Vehicle Exterior" -> "TR1bul97.pdf" that's the backup light EWD, also look at "Drivetrain" -> "TR1ect5vz97.pdf" that's the EWD for the automatic transmission. What you need to do, is cut off the Park/Neutral Position Switch (which plugs into the automatic transmission) as close to the connector as you can (you're going to throw that plug away), then isolate the R-Y wire from that bundle (that's your reverse wire), and solder the reverse connector from your 3.0 transmission to that R-Y wire.

For the 4x4 circuit:
There are 2 plugs on the 3.4 harness that connect to the transfer case, one for 4WD detection (to see if the shifter is in 4H or 4L, this is the one you want), the other is a 4L detection switch (you'll ignore this one). The 3.4 4wd detection switch will have 2 wires, one W-B (ground) and one G-R, the 3.0 will only have one connector with a W-B wire and a G-Y or G-W wire coming out of it; simply cut off the 3.4 connector (close to the plug) then solder your connector from your 3.0 harness and match the colors.

Both of these will be down under the truck close to the transmission.

 

Thanks that's exactly what I was after.