Chapter 5

Wiring for Dummies

Sorry for the pun, but wiring is one of the most complicated and ominous parts of a car that can scare the most adventurous person away. I wanted my car to work like factory, so that means that the cruise and starter had to work differently. The starter has to keep the car from starting until the clutch pedal is pressed, and the cruise has to work. It has to shut down when the clutch is depressed so the engine won't over-rev. and blow. So not only did I have to figure out the way to wire the car up, but I also had to come up with a way to do it so that someone could follow me and not need an engineering degree to understand what I was trying to accomplish. So let's get on with it.

For those of you who can read a schematic and understand the lingo I will sum it up for you so I don't bore you anymore. And then the long version with pretty pictures for all the rest. HAHA

Wording for the Savvy

Start power flows from start switch (I12 pin 7) to harness connector EB1 pin 4. Shift wire in pin 4 to pin 2 position. Next go to N1 and jumper pin1 and pin2 together. I recommend using shrink wrap connectors to reduce chance of corrosion. Install a flat four-pin start relay in R/B 4. Install start cancel switch on clutch pedal bracket. Locate connector C12 above J/B 1. Connect to start switch. Now locate C18 and connect to clutch cruise cancel switch. Next on connector N1 pin 3 and pin 4, wire to the reverse light pig-tail we picked up at the yard. Doesn't matter which way you hook it up. The last connector is O1 for o/d tape it off and seal up harness. Take her for a test drive.

Step by Step for the Novice

In the first picture here you see on the left is the neutral safety switch connector. The ungloved hand is pointing at the reverse light switch on the transmission. Now remember that I said to get the reverse light switch wire connector at the yard. Well, here is where it comes in. There are four pins on the neutral safety switch connector. Cut the connector head off and you have two large black wires, and two small red wires. Connect the two wires for the reverse light switch to the two small red wires. Make sure that the connector wires are about 6 inches long, so you have plenty of room to move the harness around. Next connect the two black wires together. This will let you start the car, even in gear so be careful. In the second picture with the torch you will see two other wires in the background. They are from the other connector on the transmission, which is overdrive. Cut it off and cut the wires off at different lengths so they won't be able to touch each other when wrapping up the harness. You will do nothing with them.

Neutral safety switch connector and rev. switch	Shrink-wrapping with a micro torch

Now that we have jumpered the neutral safety switch lets get the rest of the system in place so we don't run anything over. In the pictures below you will see the harness junction connector EB1. This connector is located in the engine compartment on the passenger side in the rear behind the strut tower. The line in the picture is the power steering hi-pressure line. Of the two connectors here we want the one on the inside, more toward the engine. As you can see there are three wires in the connector and one empty spot. We need to move the black wire from the spot it's in (pin 4) up to the empty spot (pin 2). To do this we need to remove the plug on the back with a pick or something sharp. Then you need to lift up the connector pin lock. It's the white thing inside the connector. You just lift it up with a pick and take it out, as you can see in the left picture, it's popped up and ready to remove. Once out, turn the connector so the tab is on top. Looking down in the pinhole you will see a tab that has to be picked up in order to release the wire pin. If you have trouble seeing the tab look at the empty hole to see the tab. Flip up the tab while pulling gently on the wire. Slide out the wire and move it up to the empty hole. Reinstall the lock, install the plug in the newly emptied hole and reconnect wiring harness.

Starter wire connector, passenger side of engine bay next to power steering line	back of connector w/ plug removed

At this point the car can't start again. So now we turn our attention to the inside. On the passenger floor, remove the kick panel and you will see a small relay box. It's the blue box on the left. This is R/B 4. On the left picture you see the box, as it is when you start. And the right is with the relay installed. This is all there is to do here. Reinstall the kick panel.

Relay block without start relay	Relay block with relay installed

Now for the start switch, you will see up above the main interior fuse box (J/B 1) the wire connection for the start switch. Pull it down from where it is taped to the main harness. Install the switch on the pedal with the wire coming down and out from underneath. There is a locating pin on the switch to make getting the angle correct. Clip the connector into the hole provided on the bottom left edge of the pedal bracket and connect wires. Now the start circuit is finished. You can only start the car when you press the pedal to the floor.

J/B 1 left kick panel showing clutch start wire coming down to the pedal

So, let's recap the start circuit so you can understand what you have just done. The interior harness is pretty much the same for auto and manual cars. The harness under the hood is a bit more specific for auto vs. manual. When you jumpered the neutral safety switch you made a solid path from the key to the starter with no interruptions. Now manual transmission cars use pin 2 of the connector EB1 in the corner. Automatics use pin 4. Unfortunately there is no wire for us, so we are going to rob the auto wire and use it for our needs without having to run a whole new wire. All we have to do is move the wire so we can get it on the same circuit as the relay. This way the relay will control the power running through the wire. On the interior part, the relay always had power at the box. So when we moved the wire we gave the power some place to go. But we have to ground the relay in order to get it to work. This is what the pedal switch is for. All it does is ground the relay causing the relay to turn on and start the car. Remember that all a relay is, is a way to remotely turn on a high voltage component using a low voltage switch. This reduces the size of the dash harness. Below is a schematic of the starter circuit. Notice that both automatic and manual transmission components are shown.

Now all that is left is to wire the cruise control cancel switch so the cruise will shut down when the clutch pedal is pressed. Basically all you have to do is to install the switch and hook up the wire. The connector is right there. Just remember that the switch doubles as the pedal bump stop. Don't run it down too tight and let it put pressure against the pedal. Other wise it can help to ruin the clutch. In the first picture you can see the wire for the cancel switch and the pedal stop bolt for the clutch pedal to rest against. Remove the bolt and install the switch. Screw it down until the threaded shaft just touches the rubber stopper. Lock the nut and hook up the wire. You are finished. Go for a test drive and have some fun.

Clutch cancel wire	Switch installed on pedal bracket

I hope you have enjoyed this article and have learned a few new things from it. I enjoyed converting the car a lot and found it a little challenging and yet it had a foreseeable end within reach. The wrench work can be done in a weekend and the wiring can be done in the same weekend if you have researched the harness and have the switches on hand. All the responsibility for safety features and wiring is yours. I did this to my car and wrote this article to share my experiences with you and offer this only as a means to inspire you. So if you blow you're car up or burn it down don't blame me. Follow the schematics for your specific vehicle. But I can tell you that this conversion has improved my fuel mileage and over all performance. Not to mention shave off a lot of weight.

Scott MDT

Comments submitted on the messageboard:

Hooligan
Supplement to ScottMDT's awesome Auto-manual swap
write up.
Mon Sep 8 14:56:58 2003

Hello all,
Here is a short addendum to ScottMDT's write up, my
car is a 92 and the wiring was a bit different. That's
about, except for some other tips. Good luck!

Some part numbers left out/parts left out:

Flywheel bolts: 90105-10071
Pressure plate bolts: 90119-08079
Slave cylinder rod (not included with a new slave
cylinder): 31473-32010
Upper clutch hard line: 31481-20600
Lower clutch hard line: 31482-20400
Various clips/brackets for clutch lines: If you can't
pull of a used car, go to dealer, they should be under
$50.

-Buy master cylinder, rubber clutch line, and slave
cylinder new. They are hard to find used and in good
condition because they are easily damaged. Check
around at your dealer and parts stores and spend what
youd like. Keep in mind that this project may take
over 30 days, so a warranty that lasts that long might
not do you any good.
-Find a junkyard car and get the following: shifter
assembly and cables, clutch and brake pedals,
transmission mount (top and driver's side of the
transmission), green starter relay in passenger kick
panel, clutch hard lines (hard to find in the US new
and also relatively expensive) and any/all hardware
that is related. There are many odd sized bolts that
you will need.
-Plan on spending a lot more time if you need to buy
parts new. Average wait to get new parts in is
probably 3 days, but I had to wait for over 2 weeks to
get my clutch lines in because nobody had them in the
US (they ended up coming from Japan).
-In my 1992 GT, although the underhood wiring was
correct, none of the wiring was in the car that the
write up uses. The starter relay was wired in near the
driver (I cant give specifics, but it gets power and
ground, a wire from the clutch pedal bracket to know
when the clutch is down, and a wire to send power to
the starter when the clutch is down). Clutch cruise
cancel switch must be wired in series after the brake
cruise cancel switch.

Let me know if you need clarification or have any
questions.

Thanks!
Dave

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