DigitalSynthesis

In the process of my TII conversion, I've purchased a new engine wiring harness (yeah, I paid the $650 from Mazda for it -- I wanted a new one hearing how brittle the old used ones are sitting right by that turbo and all). Anyway, I go to test fit it and I notice that where the harness comes in from the firewall there are two yellow connectors that go to a harness in the dash. One of these connectors is a transparent brownish yellow and the other is a bright solid yellow. In the bright yellow connector on my 89 'vert (the one IN the dash) it is separated into a number of "blocks" of pins. The center "block" (where the retaining clip is) has no wires running to it. On the TII HARNESS, there are three wires in this area, and it further appears to be pinned out "upside down" relative to the other harness, e.g. it will fit, but the retaining clip is on the opposite side of the connector from where it was originally.

Does anyone have a wiring diagram featuring this set of connectors and does anyone have any information on whether this is a simple rewire -> repin or must I swap out my entire dash harness as well ( ) ? I've read all the TII conversion writeups I can find and cannot locate this seemingly important piece of information.

FWIW the harness I ordered is mazda's most recent revision of the 89-91 TII wiring harness N370-18-05ZD. The dash harness that I'm talking about appears to be or is equivalent in function to part number FC33-67-030E. Both are featured in section 6701/6702 of the partsfiche if you happen to have a copy.

BTW, I am very good at wiring, soldering, etc. so I'm perfectly willing to use a diagram and figure stuff out I just don't have a diagram that details this connection for me.

Thanks much!!!

Icemark

Do you have the plug numbers of the plug in question?

DigitalSynthesis

I can't find the plug numbers in the partsfiche. Is there another place I could look for them?

HAILERS

Mispost..ignore

Changed my mind. I have access to a 90 fsm with the connectors shown in the Electrical section. Give us a clue. How many wires in this plug altogether. Then give me an idea if I'm looking at the same plug by giving me the colors of the two wires at one end or the other of the plug. Such as RG above a RL wire.

Icemark

I have only done S4 N/A to Turbo conversions, but in that swap you do need to swap dash harnesses or move pins and other minor re-wiring.

You need to know exactly what plugs to see if they are cross compatible. Remember the 90-91 'verts use a very different harnesses than the coupes.

From what you are describing it sounds like X-10 and X-11. Do you have the number of pins in each plug (pins are plug holes, regardless of if there are wires in them- but rather if there could be wires in them) and exactly where they plug in?

6701 and 6702 of the parts fiche are next to useless as they don't provide anything other than the part numbers for the harness.

I am surprised that if you bought the harness that you didn't buy at least a 90-91 wiring manual.

RotaryResurrection

iTrader: (8)

You do not need to do any rewiring or modification. All 89-91 cars can directly swap between turbo and NA harnesses. I have verified this on my own89 convertible. Just plug it in and go on...don't worry about what wires are there or not.

turbo88vert

Resurection is right. I have a friend of mine that did a T2 swap into a 90vert and all he did was plug them in!
One quick question Resurrection. Can you also just plug the connectors together doing a T2 conversion into a s4 vert, or do you have to do some rewireing there?

RotaryResurrection

iTrader: (8)

The wiring changes necessary for an s4 are explained here:

www.rotaryresurrection.com/turboconversion.htm

DigitalSynthesis

Well dammit if there's a wiring manual, where do I get it? Is there a copy online somewhere or do I just go to Mazda and say "yo I want a wiring manual?" I think with that I could figure out the answer to my question! lol.... thanks everybody... let me know how to get one of these magical books.

HAILERS

MAZDATRIX.com sells the manual with the diagrams.

DigitalSynthesis

Okay I have figured it out. For everybody's future reference the official differences for a Manual Transmission S5 (89-91) RX-7 according to the wiring diagrams for connector FEM-02 (the large bright yellow connector in the location I previously described) are:

** NOTE: [F] refers to the connectors on the Front harness which, non-intuitively in this case, means the harness that is connected to the CAR. [EM] is the emissions harness which is the harness that runs through the firewall and to the engine bay.

An L/W + L/G [F] ==> G/Y + Br/B [EM] pair is for the boost meter. Unless you are swapping the console as well you do not need to worry about these lines being run.

A G/R [F] ==> G/B [EM] wire which is for the electronic fan. My vehicle did not come with an electronic fan (except for the a/c fan which is apparently different?) and thus does not have this G/R wire on the F connector.

A B + B [EM] ==> * + * [F] set on the NON TURBO model which obviously does nothing changes to * + * ==> * + * on the turbo. This set apparently exists (on the NA models) for the A/T if the F harness is so equipped.

These are the only differences I was able to ascertain between these versions of the harnesses. Connector FEM-01 (the pale translucent yellow connector) seems to have no differences across these models.

Therefore the aforementioned wisdom of "plug+play" is correct, and now justifiably so. Hope this helps somebody else out at some point.

RotaryResurrection

iTrader: (8)

Good that you figured out all that for us, good info. However, I don't see why you couldn't have just taken our word for it

DigitalSynthesis

I'm a network security consultant by trade. I never take anyone's word without checking it out. Nothing personal whatsoever. I just wanted to know what I was "missing".

RotaryResurrection

iTrader: (8)

That's the way I am about some things...and other things, not. IF enough people tell me something, I generally believe it. I try to judge a) what is being said, and b) who is doing the saying, before I take their word or reject it.

Anyway, good info for future s5 na-->t2 swappers out there.

kilous

i recently bought a T2 engine from ebay, i want to swap it with my N/A Engine in my 1991 rx-7. Well, when i recieved the T2, the wiring harness was cut on it. i have read the past forums but i just want to make sure, can i use my N/A wiring harness on the T2 engine???
thanks

HAILERS

It makes one wonder what you would do for the Turbo Duty Solenoid, what with it being a n/a harness? Not a big deal though. I just bumped your post to the top.

kilous

I just want to know if i can hook up the N/A engine harness to my T2 engine!!!!! Please help me. i want to drive it really bad.
thanks

RotaryResurrection

iTrader: (8)

run a midpipe, which everyone does when converting anyway, and exceed the stock 8psi duty regulated boost levels regardless.

Yes you can use the NA harness, I think you have to swap a pin or 2 for the knock sensor. Hunt down copies of the FSM ecu pinout diagrams for both NA and turbo models and compare pinout positions/wire function for each, note the differences, and make any necessary changes.

HAILERS

Like they say, just hook it up the the turbo engine. It'll work fine.

As for the Duty Cycle Solenoid for the turbo, the wire for it (IF you install a Turbo ECU) goes to 3R on the ECU, which WAS used by the non turbo for the 6 port iinduction system. So........that Six Port Induction solenoid could now become the Duty cycle Solenoid for the turbo engine.

Also you won't have a VDI on the turbo engine, so if you follow the wires, you find that it used pin 2M on the non turbo ECU. The TURBO ECU uses this pin f9r the KNOCK sensor. So all you'd need to do is extract the wire out of the VDI solenoid and couple it to the output wire of the Knock Sensor. Done.

There's other ECU pin changes b/t the Turbo and Non Turbo but they are not to be worrried about at all...........unless you had a automatic then you'd unplug an item or two.

That's for S5. S4 are a little more involved.

kilous

thx alot for the information, that really helped. thanks alot. I will probably have another question or two in about a couple days, because i just yanked my old engine out and i just put the new S5 T2 in and mounted it up, now comes the harness game, so ill be posting, please check back on me. First time ever doing an engine swap. so if you have any pointers than tell me plz.

once again thx alot.