6G Celicas Forums

I keep hearing everyone that its ok to pay 500 bucks. Although i dont agree with that, its always your choice. Dont care what you spend your money in.

I had no experience with automotive wiring. But all in all, it takes time, dedication, patience, and most of all Microsoft paint.

If you can read a map, without using GPS then you should be able to understand wiring. If you are the GPS type person, Get out of here.

Toyota has made it simple even publishing these wiring diagrams and color coding it for "BEGGINERS"

Yes Microsoft paint, makes things easier. If you want to have a reliable guideline, you need to PAINT. Squibbles, scrabbles, exel notes, templates, those tend to confuse you... A Diagram is easier to follow and easy to make.

Again with the map analogy, write down directions and follow them while driving, or see a map. If you want to use your GPS, get out of here.



While its a long process to do one, you will know exactly when a problem arises, how to fix it, where to look for it. There is nothing more frustrating than following the gremlins others have made, and it costs time and money. Shipping the harness back and forth for repair, revision and etc. But her its your money, and you have a lot huh?

If you still have those 500 buck, its ok to spend them that way! and when your harness has a problem, enjoy your gremlins or spend more money....

SO ENOUGH OF BABBLE

First step you will need, is the EWD which stands for electrical wiring diagram. If you can get a PDF version, its even better, it saves you time..... you need one for your car, and for the car of the engine you are swapping... or at least the engine control diagram



Once you have found the diagram you need, you'll notice, that its spread across several pages, and its difficult to follow. that is where Microsoft paint comes in.... Screen shot and paste as needed.

This is the MR2 Ignition and Start wiring diagram, its in 2 pages, and I just made it into one......




The newer PDF wiring diagrams may be easier to follow.... They are friendly to the EYE. It is very important to learn the relays you will see in wiring diagrams...

This is the 2007 RAV4 ignition diagram, spread over 3 pages... I also included the most common relays images. Toyota has a lot of part numbers for relays, that is non important, as long as they are simple relay circuits, and you use the correct voltage, you can use any similar function relay



Its important also to study other signs and symbols you see on the diagrams, like switches, terminals. Locate the Names of the plugs, and the pin location of the wire. Its usually located on the first pages of the manual.

So why paint, because i can modify the wiring diagram to my wishes.... By drawing and making electrical connections as I need.

the following is an example, done in a rush, of the same MR2 diagram without the auto tragic components. I removed the most abhorrent option in a car.



By removing the unnecessary mumbo jumbo you can focus on what you need to see. Some diagrams include both engines, on a same diagram.. (5sfe and 7AFE) Just remove the part you dont care for.

The diagram you are looking for to start your swap, is the Engine control module, the Ignition and Start, and others that you will need, such as charging(new alternator) etc.


Are you confused yet?

there are two parts to a Wiring circuits, that I found.

1. the complicated part.... will see in a few lines below.

2. the Easy part. Why do I call it the easy part. Because the wires go back and forth in a simple way between the ECU and the part they service...

This is an example of the Easy part. There is nothing to it. Simple connections, here and there. from the IAC to engine, usually a simple wire, no extra connections junctions or splices. These are the most numerous ones. But thankfully the easiest one.



These basically connect sensors or actuators to the engine. its easy to detect problems. You will need a Ohm Meter. Google, if you dont know what that is, i wont put a picture.

With an ohm meter, you are looking for connectivity. one end of the wire to the other end of the wire, if the wire is broken, split or damaged, you will know....


The important part of wiring a car, and its the most complicated one, its the integration of the new engine control module, with the Ignition and start system of your car, and with the other components in the cockpit such as the tachometer, guages, and other connections.

this is the most critical part, but if you draw it it will guide you. Mind you it took me 3 weeks to complete the wiring diagram for the 2gr, but after that its easy to understand. And even made annotations where the splices were made on my harness, so i can trace errors...

This is an example of a portion of the ignition and start of my current engine...



So whats needed to do. In my case, i had to add 3 extra relays. They are basically a switch. I used existing relays in my engine bay for a different purpose.

example. In my celica, the EFI Fuse and relay, where used as the Ignition 2 Relay and fuse, because The Rav4 Called for a IG2 relay, to the inyectors. I decided to do the EFI relay on a separate pathway, because this relay controlled the Circuit opening relay, fuel pump relay and the A/F relay, and it was easier to have them all together or close by to avoid significant harness modifications... There were empty fuse bays, and created a line from there.

Wend to the local yard and got this from a corolla...



there it is, it sounds easy than it actually is. but it was fun to do.....

You can always write down your notes on a separate sheet of paper. but i feel its easy to always read a map....

this sucker took a long time. But thanks to this, I can understand how an engine works, and how to wire any other engine.... I save those 500 dollars to take the family out....

Figure Id contribute one last time, since I see this question asked, and hear all the time pay 500 bucks answer. If you still want to pay 500 bucks, its because you did not read this, you dont like challenges, and you got money to throw away..

To long, didn't read.

wiregapinc.com

A multi-meter is your BEST friend when doing anything electrical....

But even with one, it took me 3 days to figure out that I wired the brake lights to the fuel pump becuase the wires are right next to eachother in the connector....

But I'm dumb, so...

Now that's funny! 😂😂😂

It's the truth too. I got it to run off a jumper wire straight to the fuel pump and was like, "why are the brake lights on???"

Even with that, it still didn't dawn on me.

But thats how you learned. The first go around, the car would not start, after careful revision, I had missed a ground. then I decided to make this ground better, as i only attached it to the wall.

I cam up with the Idea of using the EA1 Plug, there is a ground there.

It worked, but when car reached operating temp, that ground gut cut off, and shut my car down, this happened 5 miles away from home. Had to trailer car back home lol....

then it started again, then shut off. After careful revision, i had used the temp sensor ground.

I should have traced that ground completely.

But anyways this is how i did it. nothing out of the ordinary.....

Let me add my two cents in here.

I spent the $500, to probably the most widely recognized "guru" of swap harnesses: Doug Copeland/Wiregap. Besides not returning my fuse box, spark plug wire stays, and alternator housing wire stays, I had no accomodation for intercooler level/pump (code 54 all the live-long day) and my Engine Coolant Temperatiure Sensor wire was pinned to throttle position sensor. There were several broken connectors as well.

In the end, I had to learn it all anyway ... just to fix the errors of the "pro". But for certain: it is a good knowledge base to possess. If you plan on keeping your swapped car for any length of time, knowing its wiring is essential to troubleshooting the everyday gremlins we are bound to find as we enjoy our machines.

Save the money. Do it yourself. It is "doable", for certain.

J3rkyBoy