How To: 5 Speed Swap in Convertibles (and other S13s)

[jackash002]

Well.. it seemed like the wires were a lot longer since they reached from under the hood into the pass window/door, but under the car they don't reach through the shifter hole as i thought it might.. so im not sure if it is worth the work to extend the wires on the factory auto switch.. maybe just make wire entrance through firewall rather then going underneath and through..

but it def. works as a kill switch if out of the park position while still giving power to evertrhing else, and the top works in park position, but not in others, haven't looked at reverse lights to see if it is controlled by that switch or another pigtail on auto tranny.. im sure it's on here if searched for, not asking just updating from last post..

if someone were to use the auto tranny wiring, instead of the manual, the plugs would be left exposed which wouldn't be good for future use or if needed. So i would suggest shrink wrapping them or something..?

on to read the wiring diagram for the first time.. lol

[music24]

the manual harness does not cover the plugs so leaving them exposed will be fine. I would how ever cover up the connector terminals of the plugs and tape up the wires so they dont dangle in the wind becoming brittle.

Im interested in seeing pictures of your design. As a personal opinion only, that switch idea just seems like to much work to drive the car day in and day out. If you are using it as a kill switch purpose, take the the overdrive button of the auto shifter and connect it to the park wires of the auto harness and hide the switch under carpet where only you can tell its there, so when you get in the car just push that random spot on the carpet and car starts magically. Just an idea.

Any insight to cruise control wiring anyone?

[music24]

New insight to the ASCD system that should make retaining the system a breeze. There is an Inhibitor relay underneath the the stock air box.
Labeled "N&P / Clutch"



Pull out the relay



Now using a short wire and a spade connector at each end, connect terminal three and four at the harness end, pictured below (Numbers are located on the inside of the relay, match the number to harness connector). See picture.



This causes the ASCD Control Module to think its not in Drive or Neutral, therefore allowing cruise to work. (it is at this point that you can wire in the 4th and 5th gear position sensors instead of the jumper wire, so the cruise will only work in fourth and fifth gear). With the jumper in place, I tested my car with a test drive and Cruise control worked normally under every possible condition. After stopping and removing the jumper wire, cruise would turn on but would not activate and hold speed. The next step to making cruise control factory is wiring the clutch pedal. Im going to take another ASCD cancel switch and put in onto my clutch pedal where the metal stopper is (pictured below). Then I will connect this second cancel switch in parallel with the ASCD Cancel switch on the Brake pedal. This way, as soon as either clutch pedal is depressed or the brake pedal is depressed, Cruise Control is turned off.

Switch on the left is the Clutch interlock switch (Going to be wired to the connector that needs to be looped to get the car to start, aka cant start car with out clutch pedal pressed in), Switch on the right is the ASCD Second Cancel switch in place of metal stopper, going to be connected in parallel with ASCD Cancel switch on the Brake pedal.


After doing more pin testing with the only two wires that connect the A/T Control Unit to the ASCD Control Unit (Colors:Green+White{Pin 13 of ASCD Control Unit} and Yellow{Pin 12 of ASCD Control Unit) I got the following results:

Yellow wire = Constant 9.2V as soon as the car is turned on. Never does it fluctuate during any driving condition or Cruise control function.

Green+White wire = 12.8V (fluctuates slightly randomly) as soon as the Cruise Control is set to hold speed.

Theoretical Conclusion: Yellow wire lets the A/T ECU know that ASCD COntrol unit is present and is ready, and Green+White wire tells the A/T ECU that at that moment that when those 12.8V reach the A/T ECU, a speed has been set and that the A/T ECU needs to keep the speed and throttle open at that exact position to maintain that speed.

Overall Conclusion: To have functioning ASCD System, Jumper the terminals at the inhibitor relay, and Connect another ASCD Cancel switch in parallel to the one that is on the brake pedal and Install the second switch on the clutch pedal in place of the metal stopper.

[dccse3k]

can someone re-up the pictures on the 1st post?

[northstar ninja]

I'm going a different route for the cruise control, reverse lights and interlock. I cut the 5 speed harness off the donor car (a ka24e) and am using that for all of the actuation. I'm wiring the interlock to the neutral position safety switch, the reverse gear sensor to the original auto wiring, that went to the automatic gear selector, and wiring the 5th gear position switch back up so cruise control works. Everything should work properly when I'm done, and it'll look as close to factory as possible



I'll take pics later if anyone is interested.

On a side note the KA24E transmission doesn't have a 4th position gear switch, only a 5th gear position switch.

[music24]

Just place a jumper wire instead of the relay and your wiring is done. Cruise will work after you are going faster than 30mph in any gear, just like it would in a manual car. Manual Car wont have that relay, there fore it would look more factory. Then add a clutch cancel switch so when you press the clutch the cruise wont rev your engine to red line. Its what I did on my car, and it works great, and it was simple.

Dont use manual wiring either, your engine bay will look like crap with all the wiring. The four plugs you see on the fuse box, you will remove that entire harness that connects to those four plugs, cleaning up the engine bay so much nicer.

[music24]

Im retarded, clutch cancel switch should go in in series with the brake pedal cancel switch

[93Vert]

the pictures are still down, can anyone fix that?

[biggie]

the pictures are still down, can anyone fix that?

We have tried, no luck so far.

[S13_RB25]

I have a question if i get a 5 speed ECU would that make things easier??? Also on my red hatch, its 89, there is a little button that the clutch pedal press down on. What is that for??

[northstar ninja]

the 5 spd and automatic ecus are pinned differently. if you ran a 5 speed harness and ecu it'd work

[music24]

CLutch pedal button = clutch interlock. Its designed so you have to push down on the clutch pedal in order for the car to start (so you dont start in gear and jerk forward, came only on US models). You can wire it into your auto swap, but the original system and idea causes more issues than good. Many times the sensor will fail and you will not start your car until you jumper the switch. Also if you are ever stuck at an intersection and your engine wont start, you can use your starter motor to pull you out out of the way. Cant do that if you have the switch wired up.

[S13_RB25]

Is there any way to wire the auto harness up with the manual ECU?? I did see a diagram for a s14 somewhere but is there one for s13?? And would i need to do that little button mod if i do a auto to manual with a manual ecu??

Sorry if these are noob questions...

[music24]

Auto ecu do not have the same pin outs. Im sure your car will still work if you plug in your Manual ECU but some things wont work. I remember looking at the electronic schematics of S13 and seeing that a one of the pins on a manual ecu goes to rear defroster, while on an auto it goes else where. That was one of the few differences that I saw. And no, you do not need to add the interlock mod with a Manual ecu. Unless you have a donor car and you would like to do excessive amount of extra work for the same results, just wire up the car like described in this thread, drive it around, see if it matches your expectations, and then fix it as needed per your desires.

[S13_RB25]

OK thank you so much and is there a diagram that i can look at that shows what each pin out is for or what ever??

[biggie]

First I've heard of this. The AT and MT ECUs should be the same when used in a 5spd car.

You can DL the FSMs for pinouts:

http://www.nicoclub.com/FSM/240sx/

[Hijacker]

I've been working on auto conversions for going on 7 years now, and I've never seen or experienced what you've just written about. I double checked my ECM pinouts just to be on the safe side, and while there are a few pins that are written in as auto only, or have the lines divided to show where the wire would go on a manual car versus an auto car, I didn't see anything that screams "pinouts are different". I double checked the rear defroster example you gave as well, and there are no pins on the ECU pinout that go there, and in the EL section dealing with the rear defroster, it shows the wiring diagram to not include the ECM. Could you provide me with the ECM diagrams you were using? I know the S14s run random things through the ECM, but that's thanks to OBD-II. I'm more or less intrigued.

There are no glaring differentiations in the two types of ECMs. The ATCU takes care of all things auto trans, so you don't really need to worry about the fact that the inhibitor is no longer hooked up, or that the kickdown switches aren't hooked up. The only thing is that you can't have a manual ECM run a car still using an auto trans, only because there are connections between the ATCU and the ECM that must communicate in order for it to work properly.

[S13_RB25]

I've been working on auto conversions for going on 7 years now, and I've never seen or experienced what you've just written about. I double checked my ECM pinouts just to be on the safe side, and while there are a few pins that are written in as auto only, or have the lines divided to show where the wire would go on a manual car versus an auto car, I didn't see anything that screams "pinouts are different". I double checked the rear defroster example you gave as well, and there are no pins on the ECU pinout that go there, and in the EL section dealing with the rear defroster, it shows the wiring diagram to not include the ECM. Could you provide me with the ECM diagrams you were using? I know the S14s run random things through the ECM, but that's thanks to OBD-II. I'm more or less intrigued.

There are no glaring differentiations in the two types of ECMs. The ATCU takes care of all things auto trans, so you don't really need to worry about the fact that the inhibitor is no longer hooked up, or that the kickdown switches aren't hooked up. The only thing is that you can't have a manual ECM run a car still using an auto trans, only because there are connections between the ATCU and the ECM that must communicate in order for it to work properly.

So let me get this straight. I can use the 5 speed ECU without a problem and won't have to worry about somethings not working like music24 said and also would I still have to wire the lights up to make them work right??

[biggie]

Yes either MT or AT. What lights?

[S13_RB25]

The reverse and brake lights, like the diagram shows with green and brown wire..

[btm88]

You'll still have to wire up the reverse lights. Brakes lights should work with no extra work needed. Seriously just follow the write-up and you will be more than okay.

[S13_RB25]

Awesome thanks for the help guys, will be doing this in the coming weeks.

[music24]

There seems to be some confusion about the word pin-out. Yes the both types of ECUs have the same pins in the same pin locations, yet some of the pins go to different locations of the car. If the the ECUs are the same just re use your auto one and forget it. I have been using my Auto ecu for the last month and have not seen any issues. The only weird thing is the rate at which the RPMs drop when they get around 1.5k, they slowly fall instead of dropping in any other RPM range. It must the the auto Throttle sensor or either ATCU or ECU. I have to do some testing to figure out. Follow the instructions I gave to get the cruise control to work. Ask for details if you need more clarification.

[CJams]

Car won’t start right now.

I have 2 cars. So I pulled the engine and transmission from a ’90 manual hatch and put it in a ’90 auto hatch. Everything is connected eccept the transmission wires and it wont start.

I spliced together the wires on the top plug behind the engine compartment fuse box. From what I understand the car should now start, but doesn’t. I turn the key and it acts like the battery is dead (or the clutch isn't pushed in). I’ve read a few threads about the wiring, but none of them make complete sense because wire colors are different and pictures just don’t look like the car I’m working on.

Wires I have:

The manual transmission wire harness coming from the plugs on the transmission:
(Note: none of these are currently connected)
Yellow with blue
Green with white
Green with orange (or brown)
Green with blue
Black
The speed sensor is also connected and seems to have a plug that it connects directly to in the engine bay on a harness..

I also clipped the wire harness from the auto transmission and have both the bottom and middle plugs for the plug behind the fuse box. Do I even need these?

Should the Manual ECU be used?

Thanks guys, I’d like to get this lil drifter rollin.

[biggie]

I assume the '89-'90 is the same as '91-'94 (as I've not touched '89-90 cars). The plug you need to run a wire to jump is under the fuse box in the front passenger side of the engine bay. That should be all that's required to start.

[CJams]

I think that jumper wire you refer to is also found at the top plug behind the fuse block (behind as in between the fuse block and the fire wall). I jumpered that and it still doesn't want to start.

There are a few plugs that have not been connected. One of them is called a "low pressure switch" up near the battery. The manual doesn't say what it's for or where it connects. oil pressure? Water pressure in radiator?

[biggie]

Oil pressue would be the only 'low pressure' switch and it is connected right at the oil filter.


This is the Park / Neutral plug that is normally mounted on the bottom of the fuse box in front passenger engine bay on '91-'94:

[CJams]

Thanks. I think the '89-90 may be different. I've read the wiring part of this thread, but my ECU wire colors are different than any i've seen. The black/red wire isn't exactly where it says it should be and the other wire that needs to be connected to the ECU is Green only on the ECU and it's said to be green/red.

I checked the ECU error codes and got this... When switched over to read errors it blinks once, then twice, then three times, then four, then five then starts over again. I waited 4-5 times for that to cycle then switched it back and both the red and green lights stay lite for ever. The red light does not go out. this leeds me to believe it's something in the wiring harness.

I still have not connected the 2 wires to the ECU from the transmission.

[Paradox]

I have been having problems with a RB20 swap into my vert, along with 5 speed swap. It is not getting fuel, but the back up lights and top are also not working. The blue/green wire should be constant power with key on as far as I understand it, but it is NOT. All fuses are ok as far as I know, we have checked things many times. Where does this wire come from? I do not want to completely disassemble the harness to track this blue/green wire.

Anyone know where that blue/green wire from inhibitor switch goes to get power?

[Hijacker]

Green/blue. Not Blue/green. It should be getting direct power from the bottom right fuse (which is powered from the ignition switch). If you're not getting power to that circuit, the issue is somewhere between the fuse box and the inhibitor plug.