Help! 3.6 conversion wiring questions
 

I am in the middle of installing a 3.6 in my 85 Carerra. Question of the day is how everyone else did the wiring!?

I was given what appears to be a complete 3.6 motor wiring harness, that runs to the interior and DME computer and relay. It does not connect to the relay panel in the back LH fender. Then I have a second hand made wiring harness that has DME fuel injection relay terminals but no computer connection.

There is a third wiring harness that is connected to a spare relay panel that could be used to replace the stock unit which is fastened in the left hand fender area in the motor compartment. The wiring loom here has been cut about 4 feet from this panel.

Everyone I have heard from I believe replaced the entire wiring harness from the relay panel, to the motor, to the DME computer under the drivers seat as a assembly. Has anyone made up their own harness like someone has done here?

My other issue is that I have sold my 3.2 motor to a gent who is going to put it in a earlier 911. He will need a wiring harness to fit the motor, computer and fuel injection relay. If I cobble up the harness in my car to make it work with the 3.6 then he is without a wiring harness and that aint gonna work either...

Would sure appreciate some ideas...

Thx,

Joe

I have some 3.0 to 3.2 wiring info at http://dowtynet.com/porsche/3_0to3_2electrical.htm . Don't know if it will help you but might help the guy who bought your motor.

wow...wish I could help you out, maybe Ingo will chime in.

That's the one area with my engine swap where I decided there is no reason to re-invent the wheel. I took the car to a guy that has done a few of these before, and let him do it. A few bucks well spent.

this web site may have some wiring info.
http://instant-g.com/Products/36Conversion/index.html
he sells a conversion kit that I have heard is very good.

There are basically two wire systems. One is the fuel injection system. This is the harness that hooks up to the various sensors on the engine and then goes into the interior of the car where it plugs into the DME "brain". You need a wiring harness adapter that powers this system. This is what Steve Timmons as well as Patrick motorsports sells. Basically this harness goes from the drivers seat area to the front trunk. It plugs into the fuel injection harness under the seat and then runs to the following items:

1) Fuel Pump
2) Battery
3) Tach
4) Switched Ignition (12 volts when the key is on or cranking)

The second "system" is the normal engine items that run through the 14 pin connector. These are oil temp, oil press, alternater, alternator control, starter solenoid, backup lights, heater fan if installed. On mine there are only six pins being used on the 14 pin plug. If you know how to use an ohm meter you can figure out what each pin on the engine side is and then match them up with the corresponding pin on the chassis side. Some "kits" come with a small jumper cable that has a 14 pin male plug on each end so that you can remove the relay panel. I left my panel in so I didn't use this setup. If you want to call me I'll be home today until about 3:30 PM eastern, then will be leaving for 3 days.

Pete
609-714-9049

again 3.6 conversion, you have to take the drivers seat out, install the dme under the seat, youhave to drill a hole in the passenger foor box or be hind the seat, the loom will run into the engine compartment, engine harness and coil wires, dont connect the dme untill your done, the home made harness goes to the fuel pump ground tach and oil, Kevin

I had 3 harnesses involved: 1) handmade from the DME to the guages/fuel pump/power; 2) from the DME that runs though the firewall and branches out in a "Y" to the engine compartment fuse panel and motor; and 3) the harness that is on the motor itself. Luckily I did nto have to modify the harnesses.

Ingo has a great understanding on this issue but I think he is still in Japan for a little while try a PM to him.

I will repeat Kevin's advice and add don't connect the battery either.

Hope this helps a little.

Joe:

I have the 14 pin connector for the 3.2 on the conversion page if you need a road map for the female side of the connector that is on your car.

You will need a similar road map for the 3.6 if it has a 14 pin connector.

As to the other issues, I haven't a clue. Sorry.

Thanks to all the information and replies.

My situation is that I did take the drivers seat out and start removing the DME computer and relay. What the problem is, is that there is another wiring loom inside the same bundle that has the harness with the DME/Relay wires. It goes futher forward and appears to go under the dash. If I pull this out to give to the gent buying the 3.2 then it appears that it takes some other needed wires with it.

My harness that goes to the DME/Relay also is a direct connnection to the motor items. I also have what appears to be two 14 pin connectors on the motor, not just one. This is a 964 motor and wonder if the wiring is different?

Will go and digest what you guys say and take a look at the harness and get back and post later tonight!

Thanks again for the help and ideas!

Joe

Joe, I see you got Steve's message, the extra harness was from a 964, originally a diagnostic port was going to be hooked up through that harness, that never happened, so as Steve said "chuck it". I believe that the pins are correct as is, but do check, please. I do not have the wiring diagrams even for my own car. That is someting that needs to be collected in one place to simplify this process. Ingo's site seems to be a step in the right direction.

Joe, as Bill recommended ,you will want to check whether the pins are correct by the factory wiring diagrams. In the original set up the pins are matched color for color. I found that the colors from a 78 to the 93 964 motor were different. You just need to be sure the functions of the wires wires at the fuse panel have the same function of the wires at the harness side.

It should be one 14 pin connector and one 12 point connector. However, I think Kevin found himself in the situation where he had two 14 pin connections but it had been fabricated by a PO.

Bill and Paul,

Thanks for the ideas. There are indeed two connectors on the LH side of the motor. Did not count the holes and assumed that they were 14 but one could be 12.

Have contacted Steve and paid for him to walk me through the wiring bundle mess as well as for the two fuel lines I need.

My problem before was that I was assuming (you know what happens when you do that!) that the DME relay and DME computer were on the same harness, which it appears they are not. Will see what happens when I get the info and parts from Steve and go from there.

If the wiring had not been a complete mess we could have gotten it switched in two days. Damm... was trying to get it in and out but thats life. Now I have time in the garage to backdate both ends of the car and maybe paint it!

Thx,

Joe

Joeaksa if your getting parts from steve youll get it figured out, here is what happen to me, when I recieved the motor and harness some things were changed, you will have two connectors in the engine compartment, one will be a big 12 pin and it will be a female on the DME harness you installed through the foot box, your cars harness will have a 14 pin male, the engine will have two plugs you guessed it a big 12 pin male and a smaller 14 pin female, the one you need to check is the one on the cars harness, after what I went through i would check them all, your motor was in a converted car, im not saying they did it wrong, just check that 14 pin female to make sure they didnt alter it, just for being safe,

The reason why i couldnt give you a answer on the fuel line is again, my car is all stock and is supposed to have 12mm fittings and it has 10mm, steve was the one that figured this out for me, i could have spliced it in but thats not the way im doing this install, I hope you already have your exhaust issue worked out, if your gonna use the 993 headers let me know i have a jig so you can flip the flanges real easy, Kevin

Kevin,

Thanks and I have a hodgepodge of connectors on the harness and motor. Going to count the pins tomorrow and try to make more progress on the wiring.

I gave up and ordered the fuel lines from Steve. Am going to use the SSI HE's for now and probably upgrade later on when I am able to save a few more bux. Cannot afford to do everything at once! I do have the 964 system that came with the motor but not sure if its worth looking at.

Thx,

Joe

Joeaksa the cross over pipe will have to be altered on the 964 pipe, i picked up a 1-5/8 B&B system with muffler on the bbs parts board at a good deal, the two connectors will be real close to each other, the other plugs go to different parts on the engine, i.e. injectors etc, if you get steves instructions it will help you alot, you can private e-mail me if you need info, stew09@aol.com, Kevin

Hi all,

The 964 conversion is something I will also be doing soon so I have been reading all your past posts and learning a great deal. I hope to buy the complete conversion set up to make my life easier, including the chip, clutch and so on.

My question here is similar to Joeaksa's on the SSI set up, I plan on using these for now just because my wallet will be empty for a while but I have read that these will also need adapting. If so in what way...will the port need lenghening to clear the engine in order to bolt to the muffler.

PS I know they are restrictive but they will do for now.

I also have the complete 964 exhaust, has anyone tried to fabricate the cross over pipe so it will work with the 915 clutch arm?

Also sorry to change the thread a little here but, the earliest chassis coversion I have seen is in a 72. is there anything else I should consider in my conversion as it is going in a 69 car which I belive will be the earliest chassis conversion. Very light car plus very powerful motor= big smiles.

Alan.UK

The engine I have is a late 964 from a 1993 C4

1971 911E
1971 911S

Joe

Here are some pictures that will hopefully help you

You should have a total of 3 wiring harnesses for the 964 engine as stated above

1) The engine should have a harness on it for the various sensors, as well as a long pigtail with connections for the starter and reverse light switch, it terminates near the fuse panel in the engine bay with these two connectors

http://forums.pelicanparts.com/uploa... 002_small.jpg
The large 12 pin connector will mate with the DME harness coming from under the drivers seat which we will see in a minute.

The small 14 pin connector will mate with the 14 pin connector on your relay panel on the chassis

http://forums.pelicanparts.com/uploa... 003_small.jpg

This it the connection you will have to check for compatibility as some of the pin outs are not compatible between the chassis and the motor, you will need to check what the pin out on your chasiss is on a site like marcesq has above

The pinout for the engine side of the 14 pin connector is
1 yellow;starter
2 not used, disconnect
3 not used
4 gn/red; oil pressure gauge
5 gn/ye; reverse light switch
6 gn/br; reverse light switch
7 bl/gn; heater fan, not needed
8 br/bl; heater fan, control signal
9 gn/wht; oil pressure warning light
10 re; relay blower motor, not needed
11 bl; alarm, not needed
12 re; a/c compressor
13 ye/gn; relay blower motor
14 re; relay fuse panel heater blower motor

The other harness is the DME harness as shown below

http://forums.pelicanparts.com/uploa... 001_small.jpg

At the center of the picture is the large 12 pin connector that connects to the mate coming off the engine shown above
The rest of the connectors mate to the motor sensors.

At the top of the picture is the large DME connector which connects to the brain, and 2 smaller connectors a 6 pin and a 14 pin, these will interface with a homemade wiring harness shown below

This is the one I made

http://forums.pelicanparts.com/uploa... 004_small.jpg

At the center is three connectors
A 14 pin and 6 pin to mate to the connectors above by the large DME connector, and another 6 pin connector that holds the DME relay. Several wires extend from this harness to the battery, the fuel pump, fuse panel, switched ignition, oil temp gauge, check engine light, fan belt breakage light etc, Ingo has a nice shematic on his site.

Hope this helps you and others. The interface harness is really quite simple to make, but then I have also done 2 of these swaps now.

Let me know if you need more help
Todd
holyoak@brandeis.edu

Todd,

I owe you big time! That helps alot and really appreciate it. Let me lay my harness's out and see how it compares with yours. I have what I have been told is a Patrick harness and hope its about the same that you have made on your own.

One question. The bottom picture of a harness in your hand, where you say "This it the connection," appears to be in the front of the car (I see the battery in the background) and I was under the impression that the 14 pin connection that I needed to "re-arrange" was coming out of the relay panel in the motor compartment. Where is this harness?

Thanks and check six,

Joe

That picture is the left rear of the car, the battery is just sitting on the floor in the hole vacated by the motor. Sorry for the confusion. Again this connector is the one that would be situated on the relay panel under the black cover at the left rear of the car.

<img src="http://members.rennlist.com/tholyoak/relay_panel.jpg">

Todd

Todd,

That helps! Did not believe it was in the front but saw the battery and wondered.

Thought you were on the way to EGKK or EGLL? Ahhh... the joy of plotting charts at 0200 at Loach!

Thx,

Joe

Joe

Since I have no idea what EGKK or EGLL is I believe you may have me confused with someone else

Todd

Todd,

Was talking with another gent yesterday who was helping me with the wiring harness and who is flying to London Gatwick or Heathrow today. Sorry and thought you were the same person.

Joe

Hey Joe:

The wires from your original 3.2 harness that go forward go to the rear of the tach (3 or 4 small wires with pins on the end.) and the alarm. The large black with the eye on the end goes to the Battery +. Then there is a 2 wire harness (Black & Green/red) that feed the coil and fuel pump respectively.

These wires go to the DME with the exeption of the coil wire that goes directly to the coil. I do not believe that you can or will use any of the wires in the original 3.2 harness.

Good luck

Marc,

Thanks and I was wondering what the forward wires were for. Sounds like I can pull all of it out and give it to the gent who is getting my 3.2!

Good info!

Joe

Todd & Marc those posts should go in the hall of fame for clearing up some issues!! Nicely done! I confess that my eyes roll back in my head when I look at boxes of Porsche wiring harnesses amd associated wiring diagrams. And I have built the wiring harnesses for 140' commercial vessels w/o any issue(at least LLoyds, the owner and the USCG have been happy)


Alan here is a pic of some SSIs that I used on my 964 transplant for a while

http://forums.pelicanparts.com/uploads/SSI4_small.jpg

The tab at B is not used at all and some work with a heavy hammer at the outer radius of the bends (area A) was all that was necessary. I did use an extra 3/8" flange to move the muffler back by that amount.

The 964 stock has long studs so yopu will want a thick flange set of SSI or if using thin flange use shorter studs.

Bill,

Which muffler did you use with the SSI's? Have heard that there is a clearance problem with the "bananna" muffler but would like to retain this one as the sound is nice yet not too loud.

Agree with you about the info on wiring. Really makes a difference! Being able to get advise from Pete, Todd and Marc really helps walk you through the process. Ingo's website as well as Rob Fix and their wiring diagrams are a big help. Would be nice to get all of this on one site and able to use as a reference for conversions. May post all this on my site when I get done!

Joe

Joseka,

I only saw this thread this morning in Tokyo. Hope you have everything figured out. If not feel free to shoot me an Email or PM.

I was also wondering about the response from Bill where he mentioned the diagnostics port. Since I am experimenting a lot with those things I was wondering if you are planning to use that original cut piece of 964 harness.

While it is not needed for the conversion I should have that big round plug I am after. I want to try and see if I can hook up a Porsche motor tester to the swapped engine.

Let me know if I could get the leftovers from the 964 harness after you are done with your swap.

Thanks,
Ingo

Ingo,

Just emptied my PM box after I saw that your PM was bounced. Thanks for trying.

At this time I am not planning on using the harness and if I do not use it will let you know. Right now I just want to get the car running and then will pick up the pieces.

Will stay in touch and your website really was a big help as well!

Joe