Body Wiring Project - Toyota MA61 Drift Car

Hello All,

I am embarking on building an entirely new body loom for my MA61 which I use for drifting. I want to declutter the mess that is my wiring as well as the previous owner and myself have done some dubious things to the wiring. I want this thread to cover the body wiring aspect of the car only so that if other people are looking for body wiring threads then it will be easier to find.

Before I waffle on about what I have learnt, I have some questions I am struggling to find the answers to:

1. I cannot find battery sized cable, 4awg or 8awg cable that is the same temperature rating as TXL. I can find 90 deg rated cable and I was thinking of covering 90 degree cable with DR25, but this seems quite pricey and was wondering what others had done? Maybe I am looking in the wrong areas, I was considering welding wire but I don't know if you can get it in ~4awg or ~8awg.

2. I have 8 (soon 9 when I add an enable relay) relays and 18 fuses. I was planning on using a Bussman 15303-4-0-4 PDM at the start of the project, but now I will require something larger. Has anyone used something larger that they think would be suitable? I would like to keep all of the fuses and relays except for the fuel pump ones in the passenger foot well nice and neatly.

3. How do others neatly terminate switches, like rocker switches for example? It seems a bit odd that you would go to all this effort to protect your harness with DR25, SCL and waterproof connectors and then just use individual female spade style connectors to connect switches? I was hoping to find a switch housing like how you can buy a mounting receptical for a 5 pin relay. Or can you get switches with wiring tails?

4. Has anyone had experience buying toyota non-waterproof body terminals? I can find all of the housing part numbers by using the following:

https://www.toyota-tech.eu/wire_harness_rm/RM06H0E.pdf

But the description of the terminals is for example "6.3" and it's female. This relates to the width of the male terminal, but if I go out and buy some 6.3 female blade style terminals from Narva or something, will the tabs be in the correct place? Do you just have to buy some terminals and see if they fit? Trial and error? Or is there a better way.

Also a terminal for the dash connectors is an 'FTP' terminal and it presses against a flexible PCB on the back of the dash. If anyone knows what that stands for that would be handy as I will currently have to splice onto the old wires, as I have no idea how to find those terminals.

6. If you want to determine "exact" wire lengths prior to purchase then consider how I did it in my spreadsheet. In the 'connection' and 'wire length' tabs you can see what I have done. But in summary:

A. Label all of your layout branch origin points, in my case A,B,C... L.

B. Create a matrix (wire length tab) to show how far you have travelled to go from point B to E for example.

C. Use a VLOOKUP and MATCH function to pick out the distance you travelled from the matrix (connection column D and E).

D. Then add on the extra distance from each branch point to the connector, to give you all the distances (connection column F and G).

E. Collect all the wire lengths and sort them into gauge and colour (wire length).

F. Use a SUMIF function to sum the wires and divide by 2, because you have counted each wire length twice.

7. Also I cannot find TXL wire in 22AWG, so I am just going to use 22AWG Tefzel wire. Or should I just use 18AWG TXL wire which is cheaper than the 22AWG Tefzel? I'd like to make it as slim as possible, but then again the bigger TXL is cheaper and will fit in the same DTM connectors. I am not sure, what have others done?

I have done the following steps so far and learnt a few things for next time:

Created a schematic (I think this would be a good topic to add to the course)

Created the layout diagram

Created the connection document

In doing so I would recommend identifying all the functions and circuits you will need (writing them down) and then doing the schematic, but in conjunction combing through the car physically and through stock schematics to determine where the connectors are and how many there are. I got caught out a few times because I thought a connector like the rear tail light had the license plate lights in the 6 pin connector, but they where actually separate. So I had to put my rope structure back in and create new tee-offs. I also forgot a few branches like my passenger window motor.

It didn't become apparent until I was a bit further along that I needed to write down each connector in the 'connections' document, whereas I started off putting in all of the functions. For instance instead of putting in the rear tail light connector, I put in the: reverse lights, stop lights, driving light when you turn the headlights on etc... and then had to tidy it up in the connections document later. You can see in my schematic that all the lights are split up still.

Another aspect of the build that must be decided is, where do you put the 'Main EFI' and 'Enable' relays, because you can put them in the body loom and then provide the ecu with power and trigger signals to fire it up, or you can put them in the ECU wiring like what was done in the practical wiring course. At the moment I am half way in between as you can see in the connection document because there is no enable relay. But I think I have decided to include one in the body loom mainly because I will want to drive the car before I start work on the engine loom and this is how it came from the factory.

I have also just realised writing this that I have wired (on paper) my headlight switch a bit weird. The MA61 has pop up headlights and so I wanted to use a DPDT switch to either turn the headlight on or the park lights, as explained in one of Zac's webinars. But then I need some way of actuating the headlight retract motors, so I thought I'd get a 3 pole dual throw switch (Probably expensive) and use the 3rd pole to actuate the retract motors. I have just realised that when I flick the switch up, the head lights will pop up and the headlights will turn on (Great!), but I have to push the button to the down position for the headlights to pop down, which will turn the park lights on, then back to the middle position to turn the parks off. I mean it would work, but not quite what I had intended.

If you have got to the end, please let me know what you think, especially those that have done this thing before and have tips or resource.

I think the same with your point 3, Toogle switches with wiring tail are far more secure for the job you are planing to do.

I like to use that way , here are a couple of options . and thanks for share the Toyota repair wiring manual, very useful .

https://www.summitracing.com/int/parts/pco-5547pt/overview/

https://www.summitracing.com/int/parts/prf-80530/overview/