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Subject Manual Conversion Wiring Guide
Posted by Gold300zx on November 16, 2010 at 12:28 PM
  This message has been viewed 13418 times.
Message In the beginning of 2005 I did an Automatic>Manual Conversion and posted a guide to the wiring issues. Everything continues to work perfectly for me.

Since then I've gone on to complete my turbo conversion. Very fun! But I always have a constant stream of email asking for pictures since the old FAQ now has broken links. The following is a summary of my two guides posted. Unfortunately I don't have the old pictures so there will be no "before" photos.

I chose to use a non-turbo manual transmission along with a turbo clutch/flywheel because I had one easily available. I'll leave it to other people to argue over if the NA trans is strong enough. Mine continues to hold up with the new turbo engine. One complication with this setup was that the starter had to be shimmed to make space for the slightly larger diameter flywheel. This is now easily solvable with a shim from Z1 here and no the inner bell housing doesn’t need to be machined.

Onto the wiring....

The auto trans has a solenoid harness attached to it. This harness connects to the plugs right behind the pass headlight. This can be discarded with the automatic (You will need to cut off and save some connector). The manual transmission has one thing that concern us. The reverse sensor. The reverse sensor will be used to make your reverse lights come on. There is also a neutral sensor you can use if you install an alarm with a remote start (Read as "custom wiring") I left mine disconnected with no problems.

Now, the automatic had a lot more wires coming out of it. There is a unit called the inhibitor switch that reads the automatic transmission's sensors. We don't care about that now. Our concern is the inhibitor switch plug (The plug behind the pass side headlight with 7 wires). Cut the matching plug off of the discarded transmission harness and open it up to reveal the wires. This plug contains the 2 wires for the reverse light circuitry (Black and Green). I have been told that the colors can sometimes vary. Simply turn your key into the "on" position and touch the two wires together to check if your reverse lights come on.

All you must do now is run a new pair of wires from the black and green ones pictured on the connector to the reverse light switch on the 5pd trans. Use plastic covers, tape and zip ties to do a clean job and to keep the wires from touching the hot exhaust system. To finish it up I cut off the two extra connectors dangling behind the headlight since the automatic trans solenoids are no longer needed.

The next problem you have to deal with is the starter wiring. If you look at the wiring diagram you’ll notice that the automatic diagram has a whole extra section. The starter relay which is controlled by our old friend the "inhibitor switch" is the extra weight we need to cut. Previously the inhibitor switch used the relay to only let your starter work only while your automatic was in certain positions.

We can solve this by bypassing the starter relay in the driver side wheel well. Simply connecting the Black/White and the Black/Yellow wires (visible in picture below with blue and black wires connect to them) would allow the starter to work no matter what else is going on. But we would like to do something a little more creative. Which leads us to the clutch pedal.

What we want to do is run a set of wires from this location in the drivers wheel well, (I installed a blue and black set of wires) route them through the firewall, and to the clutch pedal switch that hopefully came with your used clutch pedal. We want to use the black Nissan switches that form a complete circuit when the button is pushed in (clutch pedal is all the way down). Now your starter will only activate if you have the clutch pedal pushed in, as it should be.

The loose connector you see in wheel well picture above was how the inhibitor switch controlled the relay. There is no reason to leave the starter relay connected since we don't care what the inhibitor switch says anymore. But if you leave it connected you will hear constant clicking. It will drive you mad. So just unplug it. You may even cut off the connector if you want to clean up the wiring.

The car still has the Cruise/Brake kill switch but if you push in just the clutch your cruise will rev the hell out of your car. To correct this we want to extent the cut off circuit to include a switch on the clutch pedal.

The brake pedal kill switch is the one closest to the passenger side (The other switch on the brake pedal is for the brake lights). You must make certain to use the correct type of switch (It should be black). The white Nissan switches are the opposite of what we need. Just make sure the circuit is complete when the switches button is pushed in.
All you need to do is cut one of the wires going to the brake/cruise kill switch, add two wires, and extend the circuit to include a clutch switch as in my picture below.

Cruise kill is a secondary concern. Your car will still function without it. So if you don't have the necessary switch you can still finish your conversion just be careful with the cruise/clutch until you get it resolved.

Another thing that you will need to disable is the cars ability to keep your key in the ignition. The automatic wouldn't let you remove the key unless it was in park, but we don't have those wires anymore. This is simple fix. Remove the steering column covers to reveal the ignition switch and it's wires. Just cut the red and black wires (pictured in red boxes below). If the key was locked in the ignition there is a red square button on the ignition switch you can push to unlock it (Circled in picture below). It’s right above the round black button you usually push to release the key.

Now it's time for those of you who pulled your engines out to start crying. You may have heard that it’s really difficult to install the hard clutch lines. Many say that you should just pull the engine. Do you really want to do that? I did a little research and found out you can use a stainless steel braided line (that was actually designated for clutch systems, 2000psi max) and there are no draw backs. Pulse, the price comes out to only 35 dollars. Just zip tie it or mount it professionally with rubber protected brackets. Fits nice and easy.

I bought my line through
Fluid Systems Engineering
The Earl’s (manufacturer) part numbers are:
63010248 for the 48 inch Speed-Flex line $23.94
592032 for a set of steel adaptors (only need one) $9.93
These parts are plug-and-play. Connectors are already on the line no need to attach them.
This line will work with the stock bolt that can be bought through Coz along with just about anything else you might be missing.

The adapter is for changing the thread to connect the line to the master cylinder. I couldn’t find a hose that didn’t require an adaptor. If you search for the part numbers on the site you’ll find them easily.

I hope this helps those who needed/will need the information and I'd like to encourage you to have fun.. whatever you do.
Remember it's your car .. do to it what YOU want.

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