There aren’t any detailed threads about this, so I wanted to show you how I extended the body plugs of the ECU wires from the 1JZ, which barely reaches into the firewall of the SC300.

**Important Notes to Follow**

-Complete this BEFORE you swap the motor.
-Extend each wire ONE BY ONE or 5 different colored wires at a time because the 1JZ wires have some duplicates that can be mixed up.
-The thicker (shielded) wires should be tied off and done last towards the body plugs, where the wires are exposed and not shielded. -You will need 200 feet of 18 gauge wires and save the 2JZGE wires, using its thicker wires to extend the 1JZ shielded wires.
-I bought the wires from Amazon for $20 each. You will need to cut 24” of wires and strip the ends of each of them.

 

Using Wire Cutters, cut 5 different wires at once.

Using Wire Strippers, strip off each end of the wires that were cut.

Here are the wires shown being cut and stripped.

 

This is where you extend the wires one at a time.
Split the 1JZ wire in half like a V shape and do the same for the extended wires.
Then cross or intertwine the V’s, for lack of a better word, like "scissor fighting".



Twist the wire that was crossed.

Loop the twisted wires around the entire connected wire.
This technique guarantees the contact of the wires.
Test the tightness by tugging on each end of the wire. If it feels loose, redo it.

Before you do the same for the other end, you need to insert 2 heat shrinks about 1.5 inch in length for each.
Do not heat these up with a heat gun just yet. Leave them loose on the extended wires.

Now that the heat shrinks are in the extended wires, you may now twist off the other end.

Once all the wires have been extended, twisted together, and with heat shrink added, use the Solder Iron and solder each extended wire.

After they are soldered, slide each heat shrink over the soldered wires and use a Heat Gun to shrink them altogether.
If you hand twist each bundle of wires per plug, where it looks rope-like, it will look cleaner and allow more space to fit into the SC300 ECU firewall. Use electrical tape and wrap each bundle after they've been twisted.

I hope this helps. Good Luck!

 

Moved to Performance and Maintenance

 

nice very proper

 

Sorry to revive this thread but I had a few questions if you’re down to message me or you could just answer em here...