Alright since there is no search I am looking for a deatiled explination on how to wire this thing up..I will be installing on thur and wireing later maybe sat or sunday...I printed out the electrical sceme on that website but that doensnt give me colors for the rpm gauge and the size wire needed and stuff..I wont be using a relay..and I have everything in my room ready to go on

-matt

 

Hope this link helps. One thing though; in the nice picture of the Harlan wiring, the relay's coil is shown going to a ground source and the other side of the coil is connected to the Harlan white wire. THIS IS WRONG - one wire on the relay's coil should go to +12 volts and the other side of the coil goes to the Harlan's White wire which provides the ground that activates the relay. Hope that's clear. You're gonna love the VI. Watch the rev limiter in 1st. hehe
http://www.vanillaice.com/webmasters/hype/mrc/mevi.htm

 

I already went to that site and printed all that stuff out and I still dont want to attempt to wire it cause i dont wanna mess anything up

I wont be using a relay..

-matt

 

Not using a relay will simplify things to the point that the only issue will be where to tap in for the tach signal. I used the tach signal going to the number 6 coil pack. It is a red and white wire. 16 gauge wire will do the job nicely.

 

I took my rpm signal from the tach. On the back of the instrument cluster there's a screw on the back of the tachometer. I soldered the rpm wire to the screw and put the screw back in place.

For instructions go here

Go to the "How 2" section and select "how to install rpm based shift light" in the performance section.

 

my RPM signal comes from the ECU.. much easier.. you can find it in the S-AFC instructions

 

I'm still confused

 

I have all the stuff I need and all the directions printed out..

Im not using a relay but I need to know what wire colors go where..

please someone help me out

-matt

 

send me your install kit.. i will wire it up with pics and send it back to you

 

It's really not that difficult. If your Harlan rpm switch is like mine, it has four wires - a bundle of three and one wire by itself. In the bundle of three, there are red, black and green wires. The red goes to a 12V source. The black goes to ground. The green wire goes to an rpm signal. I have my rpm switch in the engine bay, so it was easy for me to connect the green wire to the red and white wire of the harness going to one of the coil packs. Others have their rpm switch in the cockpit and use the rpm signal going to the tachometer or the ECU.

The one wire by itself (mine was black, but yours may be a different color) goes to a 12V source, since you are not using a relay.

I used the cigarette lighter power wire as the 12V source since it is only on when the ignition is on. There may be a switch activated 12V source somewhere in the engine bay, but I couldn't find a convenient one.

 

The harlan switch provides a ground output that is rated at .5 amps 12volts DC. It should go to the negative side of your vacuum switch or to one side of a relay coil to provide ground. Good luck - it really is simple.

 

What wire do I tap into on the coil ?? where is that wire ??

-matt

 

Each coil pack has its own harness. In the harness there are three wires, two are solid colored and one is a red and white colored wire. You can see the wires where the harness cover ends at the plastic connector. The red and white wire is the one you want to tap into.

 

Remove the plastic cover on the engine that covers the 3 cylinders towards the front of the car. Once that's off you'll see 3 clips which are each attached to an ignition coil. Each clip will have 3 wires going to it. On all of them, one wire should be red, one is black and the third one will be a different color depending on which cylinder you're looking at. Tap the green wire (tach input wire) of the Harlan switch to the different colored wire of one cylinder. I think most people attach to the cylinder that is towards the front of the car on the drivers side - that is cylinder 6 fyi. IMPORTANT: Make sure you set your Harlan switch to "coil per plug". Hope that's clear. Good luck.

 

Good stuff. The red and white wire I referred to above was for the #6 cylinder. I didn't realize it was colored differently for other cylinders.

 

I think I understand alittle better now..all I have to figure out now if where to wire the Dawes Device up to, and how to get the wire threw the fire wall..and the gauge wire to use

-matt

 

Run one wire from the Dawes device to the battery + and put a 3 amp fuse inline with it. Run the other wire of the Dawes device to the negative output of the Harlan switch (this is the wire that is alone comming out of the Harlan switch). There should be a knock out on the firewall near your throttle cable line. It will be a rubber grommet that you can remove and you'll have a nice ~3/4" pass-through. To explain the Dawes device wiring in a little more detail - with how I've told you to wire it up, it will always have a constant +12 volts going to it. It won't activate though, until it gets a ground which is provided by the negative output of the Harlan switch when it reaches the RPM you've programmed the switch to activate at.

Just get in there and start doing it. POst questions as they arise. You'll be fine.

As far as wire gauge, it's really not important since you aren't moving big amounts of current. Use 14 - 18 AWG wire and you'll be fine. If you want to use bigger (lower AWG rating) that won't hurt a thing.

 

everything is coming together now ...why cant you connect the one wire from the dawes device, that needs power, onto the one same wire that goes into the cabin and onto the cig lighter and gets power when the cars on ?

Connecting to the battery is done by just connecting to the red side on that plastic peice and putting the fuse inline with that and the dawes so it dont get too much power ??

 

If you want to hook your Dawes device up the way you mention just run two wires from the dawes device into the cabin. Run one to the cig power and the other to the Harlan output. It really doesn't matter. It would just save you a little wire to do it my way. If you hook it up the way I mentioned the fuse is just a good idea. It's not neccesarily needed but for a buck or two you can't go wrong. Most taps comming off of the RED + terminal of the battery are fused within 18". It will protect the battery from short circuiting and posing a fire hazard. If you hook up to the cig for power, it is all ready fused.

 

yea, both the dawes and the RPM switch need power, right ? Well if you run one wire from the cig lighter out to the engine bay then spice in two wires from that to go to both of them, would that work ?? probably not ?? ill just do it your way

-matt

 

Yeah, you can do it that way. In fact, I say do it that way. Hook one wire from the Dawes device to the Red wire of the Harlan and then hook the two of them to the cig power. It will work fine and I would recommned you install the rpm switch in the center console near the cig lighter. That's where I have mine personally and I have located 4 other peoples there too (I've been involved in the installation of 4 VI's). It works out great and is easy to get to to reprogram if you need to and it keeps it out of the weather.
Tell you what, when I get home later tonight from my hockey game I'll try to draw up a clear schematic and take a picture of it and post it here. Hold tight.

 

ok...so In insense I would have one wire threw the fire wall going to the cig lighter, than one off of that going to the Harlan ?? But all the wires off of the harlan will have to go back out the firwall to the engine ??? where do I run the wires threw ?? I guess underneath the center console and mount it like by my leg thats hot

-matt

 

I have my harlan under my hood with the one power wire(spliced into two) going into the cabin to the cig lighter fuse. You may have a hard time finding a hole in the firewall. I used a hole where a large wire bundle passes through the wheel well. You have to take off the plastic fender cover to gain access.

The way you plan on wiring it is a good idea. That is how I have mine and it has never failed to open up.

 

So ?? ONE ?? coming off of the cig lighter and going into the engine bay and two coming off of that ???

I still may put it in my cabin but Im waiting for that writeup cause i dont understand how all those wires will make it threw the fire wall


I dont want this thread to go to far with no search

-matt

 

You drill a hole in a convenient place in the firewall. If you have an automatic transmission, then right where the clutch master cylinder would be (that you do not have) next to the power brake booster is an easy to access place.

Another good place is behind the fender well liner down low in front of the door.

 

Yes

 

Below you will find some links to pictures I've taken. Keep in mind, I have a 1995 Maxima SE. Your car may be slightly different. Your car will definitely have a pass through on the firewall but it may be in a different spot than mine. It won't be far from where mine is though. Also, I don't think any 4th gens other than the 95s have the same vacuum attachement point that I'm using for my canistor's supply. SO, to get your vacuum source for your canistor just get a T fitting and splice into the fuel pressure regulator's vacuum line.

I have tried to show the simplest connection points for everything, that is why I'm showing you coil #1 since it won't require you to remove anything to gain access to the wiring. As the way I show it wired, you'll have three wires passing through the firewall. 1> +12 wire for vacuum switch (Dawes device) 2> RPM signal for RPM switch 3> -12 wire to vacuum switch (Dawes device) The pass through is more than big enough to accept these wires.

I would recommend using 14 - 20 AWG wire. You don't really need a big wire. You're not carrying much current in any of these wires. Also, I would use a relay from the Harlan switch but for the purpose of this thread I have left that out since most don't seem to want to use one.

Firewall pass-through point and my vacuum source


Coil hook up point


Wiring diagram (it's crude) You will hook two wires into the cigarette lighter's power wire (1 goes to Dawes device and 1 goes to Harlan switch). You will hook 1 wire to the cig's ground wire (the black wire of the Harlan switch). The Harlans output wire will go to the Dawes device. The Harlans Tach input wire will go to the coil. Hope these are clear.


Hope you find this useful.

 

Looks good
-hype

 

They look good..thanks bud..if I have any problems with it next week when I install it, hopefully good weather, I'll PM you...thanks

-matt

 

This is a good explanation for wiring the MEVI.

 

I have a Summit Rpm switch
http://static.summitracing.com/globa...sum-830450.pdf

will all this info work for this switch? Or is it just for the Harlan?

 

It will work for that, howver I find it's WAY easier to just run two wires from the selenoid right through the firewall and over to the ecu side, and than connect EVERYTHING right at the ecu, it's much easier, and I've done my share of VI's. Actually to the point that I can remember the pin-outs off the top of my head:
#5 white/green = tach signal. 25, red, power. 10, black, ground. Oh snap! Might want to double check that though. Edit: Wow, way off on the afc, lol. Anyways, #24, NOT 25, is a red wire with key-on power.

But yeah, pull the ecu covers off, cut back the tape, wiggle the wires a little to make room, find the appropriate wire, strip some back, poke it into two, insert wirethrough, solder, and tape. It's convenient because you do everything right there and you can use your rpm switch and selenoid power from the same wire, and than stuff the switch inside the car. No lie the last one I did took 20 minutes to run the wires, connect it, and solder it all up.

 

Holy thread digger!!

Those instructions are only for the Summit RPM switch.

I responded to your PM. See links that I provided....