R32 GTS4 auto to manual wiring question

[TheOrangeSkittle]

Hello, ive been unable to find any info really regarding the wiring of the inhibitor for the car to start, nearly have all my parts together now for this.

Id like to do this as proper/oem as possible, now the question I have is if I use a manual ecu for my car will I still need to fiddle with cutting wiring and soldering to get the car to start and the reverse lights to work properly?

Are the manual and auto transmission harnesses the same?

I will most likely be using a gtr box since I cant find a gts4 box anywhere.

 

Thanks for any help as im clueless when it comes to wiring!

[Duncan]

To answer your questions backwards, a GTR box is a GTS4 box.

I don't know the wiring differences and I haven't looked at it personally, but GTSBoy put up detailed wiring diagrams here:

Top left of diagram 1 shows in Auto cars the start wire from the ignition switch goes via the inhibitor switch and then to the starter motor. I don't know where it is or what it looks like, but you need to bypass that. Given the diagram doesn't show any other wires involved from the gearbox, I guess it might be at the auto trans shifter.

I can't work out the reverse lights at a quick look, but I think you need to use the reverse switch on the manual gearbox as the trigger so wiring changes will be needed unless the auto also had a reverse switch. Neutral switch should not be required.

None of that is ECU related, so swapping ECU will not help

[TheOrangeSkittle]

5 hours ago, Duncan said:

To answer your questions backwards, a GTR box is a GTS4 box.

I don't know the wiring differences and I haven't looked at it personally, but GTSBoy put up detailed wiring diagrams here:

Top left of diagram 1 shows in Auto cars the start wire from the ignition switch goes via the inhibitor switch and then to the starter motor. I don't know where it is or what it looks like, but you need to bypass that. Given the diagram doesn't show any other wires involved from the gearbox, I guess it might be at the auto trans shifter.

I can't work out the reverse lights at a quick look, but I think you need to use the reverse switch on the manual gearbox as the trigger so wiring changes will be needed unless the auto also had a reverse switch. Neutral switch should not be required.

None of that is ECU related, so swapping ECU will not help

Thanks so I guess there really is no way around it without messing with some wires huh?

I should be able to use the auto gts4 speed sensor with little to no issue though correct? The GTR trans has slight different gearing but the speed gear is same exact part number in auto and manual gts4 and in the gtr gearbox.

[Butters]

Both the body loom and trans sub loom are different between auto and manual.

You are going to need to change at least one of them.  

Most people just change the trans loom, this leaves you with un-used plugs on the auto body loom.  

Picky people will do both to tidy things up. 

 

The speed drive is mechanical, you can use which ever matches your gearing. 

[GTSBoy]

6 hours ago, TheOrangeSkittle said:

I should be able to use the auto gts4 speed sensor with little to no issue though correct?

It is vert unlikely that the speed sensor from the auto will fit into the manual. The boxes are from completely different manufacturers. They don't swap between auto and manual on any of the RWD boxes, so there's no reason to expect that they do on the AWD (which I've never stopped to think about before).

[TheOrangeSkittle]

9 hours ago, Butters said:

Both the body loom and trans sub loom are different between auto and manual.

You are going to need to change at least one of them.  

Most people just change the trans loom, this leaves you with un-used plugs on the auto body loom.  

Picky people will do both to tidy things up. 

 

The speed drive is mechanical, you can use which ever matches your gearing. 

 

I was probably going to just get a new trans loom for a gtr, since I cant find a manual gts4 one.

 

Id assume the gtr trans loom and the gts4 ones are basically the same exact thing?

Edited March 6, 2023 by TheOrangeSkittle
Screwed up the quoting

[TheOrangeSkittle]

3 hours ago, GTSBoy said:

It is vert unlikely that the speed sensor from the auto will fit into the manual. The boxes are from completely different manufacturers. They don't swap between auto and manual on any of the RWD boxes, so there's no reason to expect that they do on the AWD (which I've never stopped to think about before).

The speed sensors from the r32 gtr, r32 gts4 manual, and r32 gts4 auto share the exact same part numbers, besides the gtr one having a 20 spline and the gts4 a 21 spline. The boxes are literally the same besides a few gears that are taller in the gtr and the auto well being an auto, the transfer case is the exact same beside the whole not having a shifter bit, from what I understand.

 

[GTSBoy]

Ah. I should have thought of that. The speedo drive being on the transfer case means that the gearbox isn't part of the equation. The TX case is the same thing regardless of auto or manual.

In which case, I revoke my claim.