How To: Swap a 20v by System

5. Wiring

This is the heart of this conversion. Many 20v swaps have failed due to installers being unable to master the wiring. To make this part of the swap go more smoothly, I offer a complete plug and play solution. Here is a picture of the finished product:

It is perfectly fitted for the aw11. The air conditioning works along with the enginebay cooling fan. The 20v ecu will mount in the stock aw11 location. I test every harness on my own vehicle so that it is know to be operational and defect free before I ship it. The harness is loomed and ready to run.

The whole concept is to offer a harness that looks and fits like it was oem. Its as if you went to the Toyota dealership and ordered a stock harness, although my harness is cheaper than a dealership replacement harness. The cost is $350 and has a 100% success rate.

It’s a superior product compared to other offerings on the internet that claim to be plug and play. Competitive offerings ship mostly unloomed (ie you get a barewire harness), totally untested and have been known to contain defects. You as the end user get to sort through all the issues. Far from a hook it up in 20 minutes and turn the key proposition.

If you decide to do the wiring yourself, it is best to get an uncut 20v harness. There will be plenty to modify and change to make it work with the aw11 bodyharness, but is much easier than trying to get a cut harness to work. With a typical cut harness, you end up reconstructing a good portion of the harness. Not good if you are not pretty advanced at automotive wiring. Either way, there is a lot of soldering involved.

Here is a link to a good step by step on how to get an uncut 20v harness to work in the aw11.

http://www.padandwheels.com/mr2/blac…ng/wiring.html

Swapping a 20v 4age for a 16v 4age has become a very common practice. Aside from significant performance advantages, you will be getting a newer engine typically with much lower mileage. Parts availability for the 20v has improved over the years as well. There are a number of Toyota dealerships that specialize in JDM parts. Champion Toyota comes to mind. Almost all the parts can be purchased easily and are priced like normal USDM dealership replacement parts. Considering many mr2 replacement parts have to be ordered anyway, getting 20v parts is not much more of a hassle.

The 20v conversion is a fairly easy bolt-in swap. Perfect for those looking for a high revving engine with a wonderfully broad powerband who also want stock reliability.

This documentation in no way replaces the Toyota MR2 Repair Manuals. The purpose of this content is only to provide supplementary information to fellow MR2 enthusiasts. Midship Runabout and its contributing authors will not be held responsible for any injury or damages that may occur as the result of practicing any of the methods or procedures described within this website. Article and photo submissions are property of the contributing author.


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9 Responses

  1. Jason McDaniel says:

    Can I get contact info to buy a harness?

  2. Jimmy Lam says:

    Got a 1993 Corolla dx station wagen stick shift, would like to swap from 7afe (stock engine) to 4age 20v BT, need some tech advise and would buy a plug and play harness from you, pls contact me via the above email, much appreciate your post and have a great day.

  3. Troy says:

    Hey, I’m planning to do this swap over the summer, how do I get one of these ‘plug and play’ harnesses?

  4. Daniel says:

    I am also interested in a harness, could you please get in contact with me if its still an option. I have a mk1 mr2 with the swap already done, but it was done poorly and the harness is hacked….

  5. yerv says:

    hello there,
    I would also like to purchase one of these harnesses. Please get back to me as this wiring stuff was the only thing holding me back fromfrom finally tackling the swap

  6. Addison says:

    Hi,

    Thank you so much for your post it is very helpful! Can I buy a plug and play harness from you? I am planning on doing a silvertop swap with my aw11 soon. Thank you!

  7. daniel says:

    yet another request for a harness……is it still something you can do? can you source the original harnesses as well? thank you for your time.

  8. Michael says:

    good day,. i have a ee100 with 2E engine swapped with 4age BT,. what do i need to have my exhause pipe fixed, pls comment on sensors needed to be added and/or installed pipe sizes, for proper functionality of the engine

  9. mr220v says:

    Looks like this old writeup of mine travels far. Originally did it on mr2.com 6 years ago maybe.

    PNP harnesses can be ordered at http://www.wiregapinc.com

    I swap the 20v among other things.