S13 KA M/T wiring - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Spring Break '92 · 01-24-2009, 06:44 PM

Hello everyone. I swore my reverse lights in my 91 S13 fastback worked at one point. Its a manual. I knew that I had some switches unplugged on my tranny, I have had it up in the air many times. A friend pointed out to me that they didn't work so I checked the fuse, good--did power and ground tests at the connectors in the back--got neither of those. I planned on checking the wiring to the reverse switch and if that checked out OK, then doing a continuity test on the reverse switch. Sounds simple enough, right........?

Today I put the car up on ramps and noticed that none of the switches on the passenger side of the tranny are connected. The car always has been able to start in neutral, so that's another one. I cannot find the plugs from the wiring harness that go into any of the switches on my tranny. I have looked and felt around and there are no plugs on my car anywhere that I can find to go into any of the switches.

I have done searching on here and other forums, looking at 5 M/T conversion threads, etc., anything that might have some pictures of these plugs and cannot find pictures of what I am looking for. I have printed out pages from the FSM I have on my PC of all of these things and the only thing I have been able to match up are the switches themselves. I cannot seem to trace anything going to the tranny switches from the wiring harness. I saw a few pictures of someone doing an auto to manual conversion and I gathered that there are some plugs on the passenger side engine bay fuse box that have something to do with the tranny. There are two plugs on mine and nothing is plugged into them. Im going to take a stab in the dark here----is there some wiring link that is missing on my car that goes from the plugs on the fuse box to the switches on my tranny? Can anyone please help me out? If anyone has pictures this would be great.

projectRDM · 01-24-2009, 09:54 PM

A portion of the lower harness is missing sounds like. The alternator, starter, VSS, and OPS are all a part of the lower harness as well so someone has just removed the transmission section. Weird.

The neutral position switch has nothing to do with starting, it just tells the ECU if the gearbox isn't in gear. You don't even need it.

Spring Break '92 · 02-08-2009, 02:56 PM

OK, I found the issue. I have an S14 trans in my S13. I got myself a new lower engine harness, but this was before I realized I had an S14 trans. I discovered this when I noticed that the diagram of the trans in the S13 FSM didnt match up to what I was seeing on my car. Looking at the S14 FSM verified that. I had tried installing a new S13 lower harness yesterday, and still no reverse lights. The plugs on the new harness plug into the S14 trans. From reading your posts in another thread, looks like I might have to hardwire the reverse lights, but is there any way at all to make the S13 harness work with the S14 trans? What to do here.....

projectRDM · 02-08-2009, 03:00 PM

The transmission is the same. Period. The VSS is different but that's it. Test the reverse switch.

Spring Break '92 · 02-08-2009, 04:37 PM

The wires on the reverse switch were broken, I repaired them by soldering new wires on the connector. Tested the continuity, the switch has continuity. The only other thing I could think to do was to jump the reverse switch connector at the wiring harness and see if the lights would work. They still didn't work. One thing I did find yesterday is that with the new wiring harness plugged into the VSS, the speedo didnt work. Plugged the old harness back into the VSS and it works again. Im baffled by that one.

Spring Break '92 · 02-11-2009, 07:37 AM

I found that the lower engine wiring harness connector wires do not match up to the grey plug on the fuse box. I jumped the wires (green/blue and green/white) from connector to connector, put the car in reverse with key on and BAM, reverse lights! Now I need help finding out as to why the wiring in each connector does not match up....
Also, as I may have stated above, I got a new lower wiring harness----and some things seem to be different than the old one on the car. The old one is still in--there are old and new wiring harness connectors co-existing, because the battery is relocated to the back. The big white wire that goes from the alternator plug to the fuse box connector, is the same, but the small diameter white/red stripe wire on the new harness goes to the same connector as the transmission switches...? On the old harness, the small white/red wire is alongside the big white one coming from the alternator and plugs in at the same place on the connector at the fuse box. I know its confusing, but what Im saying is, the small white/red wire is not going to the same place as before, and that plug connector at the fuse box that the new trans. wiring harness connector plugs into sure as hell doesnt have a corresponding white/red wire for it. At this point I dont even know if my alterator is charging my battery. I have an Optima red top, and not getting a battery light on the dash. Seems as though when I first start the car, which has no trouble at all starting, the lights on my dash are just a tiny bit dimmer than normal, and then when I start driving they go to full bright. Here are some pics of the wiring:

Here is the connector that comes from the tranny reverse switch/gear position sensors plugged into the connector on the side of the fuse box.

Here is the back of the connector from the fuse box, showing the wiring that is there....

Here is the back of the connector for the lower engine wiring harness, the one that goes to the transmission wiring connectors.

As you can see, the wires dont match up.

On a somewhat related note, this is the original wiring harness connector that goes into the fuse box wiring for the alternator. This is the vehicle wiring end of the connector that plugs into the alternator. On my new lower harness the end that goes into the alternator is the same, but after that instead of this, where the two white wires plug into the fuse box wiring together, the two split up and the small white/red wire goes into the connector for the transmission wiring........

projectRDM · 02-11-2009, 05:21 PM

Car used to be an auto. The gray plug with mainly green wires is an automatic transmission plug. You've got a mix of the two it seems.

Spring Break '92 · 02-11-2009, 09:27 PM

That did occur to me, as I could think of no other reason why the wires wouldnt match up. I suppose the only thing I can really do is re-pin either of the connectors to match the other. What about the white/red alternator wire though? What does it do? Looking at the wiring schematics, it does not explain its purpose.

01-24-2009, 06:44 PM	#1
Spring Break '92 Zilvia Member Join Date: Dec 2007 Location: unconcious on Daytona Beach Posts: 180 Trader Rating: (1) Feedback Score: 1 reviews	S13 KA M/T wiring Hello everyone. I swore my reverse lights in my 91 S13 fastback worked at one point. Its a manual. I knew that I had some switches unplugged on my tranny, I have had it up in the air many times. A friend pointed out to me that they didn't work so I checked the fuse, good--did power and ground tests at the connectors in the back--got neither of those. I planned on checking the wiring to the reverse switch and if that checked out OK, then doing a continuity test on the reverse switch. Sounds simple enough, right........? Today I put the car up on ramps and noticed that none of the switches on the passenger side of the tranny are connected. The car always has been able to start in neutral, so that's another one. I cannot find the plugs from the wiring harness that go into any of the switches on my tranny. I have looked and felt around and there are no plugs on my car anywhere that I can find to go into any of the switches. I have done searching on here and other forums, looking at 5 M/T conversion threads, etc., anything that might have some pictures of these plugs and cannot find pictures of what I am looking for. I have printed out pages from the FSM I have on my PC of all of these things and the only thing I have been able to match up are the switches themselves. I cannot seem to trace anything going to the tranny switches from the wiring harness. I saw a few pictures of someone doing an auto to manual conversion and I gathered that there are some plugs on the passenger side engine bay fuse box that have something to do with the tranny. There are two plugs on mine and nothing is plugged into them. Im going to take a stab in the dark here----is there some wiring link that is missing on my car that goes from the plugs on the fuse box to the switches on my tranny? Can anyone please help me out? If anyone has pictures this would be great.

01-24-2009, 09:54 PM	#2
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 47 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	A portion of the lower harness is missing sounds like. The alternator, starter, VSS, and OPS are all a part of the lower harness as well so someone has just removed the transmission section. Weird. The neutral position switch has nothing to do with starting, it just tells the ECU if the gearbox isn't in gear. You don't even need it. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

02-08-2009, 03:00 PM	#4
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 47 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	The transmission is the same. Period. The VSS is different but that's it. Test the reverse switch. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

02-11-2009, 05:21 PM	#7
projectRDM Post Whore! Join Date: Dec 2002 Location: Atlanta Age: 47 Posts: 13,812 Trader Rating: (12) Feedback Score: 12 reviews	Car used to be an auto. The gray plug with mainly green wires is an automatic transmission plug. You've got a mix of the two it seems. __________________ FORMERLY R240NA Learn what's really going on and protect your assets now before they're gone forever: www.paypalsucks.com

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02-08-2009, 02:56 PM	#3
Spring Break '92 Zilvia Member Join Date: Dec 2007 Location: unconcious on Daytona Beach Posts: 180 Trader Rating: (1) Feedback Score: 1 reviews	OK, I found the issue. I have an S14 trans in my S13. I got myself a new lower engine harness, but this was before I realized I had an S14 trans. I discovered this when I noticed that the diagram of the trans in the S13 FSM didnt match up to what I was seeing on my car. Looking at the S14 FSM verified that. I had tried installing a new S13 lower harness yesterday, and still no reverse lights. The plugs on the new harness plug into the S14 trans. From reading your posts in another thread, looks like I might have to hardwire the reverse lights, but is there any way at all to make the S13 harness work with the S14 trans? What to do here.....

02-08-2009, 04:37 PM	#5
Spring Break '92 Zilvia Member Join Date: Dec 2007 Location: unconcious on Daytona Beach Posts: 180 Trader Rating: (1) Feedback Score: 1 reviews	The wires on the reverse switch were broken, I repaired them by soldering new wires on the connector. Tested the continuity, the switch has continuity. The only other thing I could think to do was to jump the reverse switch connector at the wiring harness and see if the lights would work. They still didn't work. One thing I did find yesterday is that with the new wiring harness plugged into the VSS, the speedo didnt work. Plugged the old harness back into the VSS and it works again. Im baffled by that one.

02-11-2009, 07:37 AM	#6
Spring Break '92 Zilvia Member Join Date: Dec 2007 Location: unconcious on Daytona Beach Posts: 180 Trader Rating: (1) Feedback Score: 1 reviews	I found that the lower engine wiring harness connector wires do not match up to the grey plug on the fuse box. I jumped the wires (green/blue and green/white) from connector to connector, put the car in reverse with key on and BAM, reverse lights! Now I need help finding out as to why the wiring in each connector does not match up.... Also, as I may have stated above, I got a new lower wiring harness----and some things seem to be different than the old one on the car. The old one is still in--there are old and new wiring harness connectors co-existing, because the battery is relocated to the back. The big white wire that goes from the alternator plug to the fuse box connector, is the same, but the small diameter white/red stripe wire on the new harness goes to the same connector as the transmission switches...? On the old harness, the small white/red wire is alongside the big white one coming from the alternator and plugs in at the same place on the connector at the fuse box. I know its confusing, but what Im saying is, the small white/red wire is not going to the same place as before, and that plug connector at the fuse box that the new trans. wiring harness connector plugs into sure as hell doesnt have a corresponding white/red wire for it. At this point I dont even know if my alterator is charging my battery. I have an Optima red top, and not getting a battery light on the dash. Seems as though when I first start the car, which has no trouble at all starting, the lights on my dash are just a tiny bit dimmer than normal, and then when I start driving they go to full bright. Here are some pics of the wiring: Here is the connector that comes from the tranny reverse switch/gear position sensors plugged into the connector on the side of the fuse box. Here is the back of the connector from the fuse box, showing the wiring that is there.... Here is the back of the connector for the lower engine wiring harness, the one that goes to the transmission wiring connectors. As you can see, the wires dont match up. On a somewhat related note, this is the original wiring harness connector that goes into the fuse box wiring for the alternator. This is the vehicle wiring end of the connector that plugs into the alternator. On my new lower harness the end that goes into the alternator is the same, but after that instead of this, where the two white wires plug into the fuse box wiring together, the two split up and the small white/red wire goes into the connector for the transmission wiring........

02-11-2009, 09:27 PM	#8
Spring Break '92 Zilvia Member Join Date: Dec 2007 Location: unconcious on Daytona Beach Posts: 180 Trader Rating: (1) Feedback Score: 1 reviews	That did occur to me, as I could think of no other reason why the wires wouldnt match up. I suppose the only thing I can really do is re-pin either of the connectors to match the other. What about the white/red alternator wire though? What does it do? Looking at the wiring schematics, it does not explain its purpose.