S13 KA M/T switch wiring

[Ken Park]

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 transmission, 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 transmission 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 transmission. 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 transmission 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 transmission. 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 transmission? Can anyone please help me out? If anyone has pictures this would be great.

[Vegascorbin]

Check your FSM for the fold out page that shows all wiring. If you have the same fsm I have (from this site) then the ECU connector will be on the left and the trans switches will be on the lower right.

(Just remembered that I have my FSM image rotated 90 deg counterclockwise)

Hope this helps

[snake240]

i used this for my reverse lights.zerothread?id=77784

[Ken Park]

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.

What it is, is that I have discovered that the lower harness on my car had been hacked, only leaving the wiring and plugs for the starter and alternator. The battery had been relocated when I bought the car and since the negative terminal is inclusive in the lower harness, it looks like the guy I bought it from removed it along with the transmission wiring and plugs. I ordered a new lower harness.

[Ken Park]

Today I installed the new harness. The battery on my car is relocated, the two main cables for the starter and battery positive were not needed. I ended up taking the new harness apart and using everything but those. I got everything on the transmission plugged in, except for one plug, which I believe is the 4th gear sensor plug. Still my reverse lights dont work. The wires on the connector for the switch itself were broken, I repaired them, tested the switch. Got continuity at the connector when the key was on and trans was in reverse. So the switch is good. Everything pertinent is plugged in to the harness connectors at the fuse box. Even checked the fuse again, fuse is good. Now the speedometer does not work, when it did before...? Tomorrow I am going to hook up my laptop and Consult program and see what is happening with the switches. Im stumped.
Modified by Ken Park at 9:15 PM 2/7/2009

[Ken Park]

OK, figured out I have an S14 trans on my S13. I have searched and cannot find any write ups on how to make the S13 wiring work with the S14 trans. Anyone?

[Ken Park]

I hope I dont look too redundant coming back to this thread to post, but I have made some good progress this afternoon. 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.
Modified by Ken Park at 9:51 AM 2/11/2009

[Ken Park]

Here is the connector that comes from the transmission 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........