6pin or 3pin CD box? -> 3.0 in a 71T

[K.B.]

I'm puttng a 78 3.0 motor with Webers into a 71T. Wondering if I should use the 71 wiring with a 3 pin permatoot CD box or try to use the wiring as it was in a 78 with a 6 pin Bosch box? Any advantage either way? I have the Bosch 6pin box but no other wiring from the 78.

Help me out guys. Edit -->Pertinant 3 pin threads here and here

Ken

[emcon5]

I don't believe the trigger in the 3.0 distributor will drive the 3 pin box.

Remember the 911 SC distributor spins the opposite direction of those that came before and after.

Tom

[Early_S_Man]

A 3-pin box won't trigger from the magnetic pickup in the SC distributor!

Here is a diagram that may help:

[K.B.]

Thanks Warren, I've seen your post . The diagram is helpful. I have some Wiring diagram links here and here .


and a quote from you post on 6pin pinout
"Here is the pinout looking into the connector with the mounting flange sitting on the hand or table ...

. 31/1 ... TD ... 31d

. A . . . . 15 . . . 7

==============

31/1 -- Power ground
31d -- Signal ground [green coax shield] for trigger signal

15 -- +14 Volt power lead

7 -- Trigger signal from distributor magnetic pickup coil

TD -- Tachometer Drive signal

A -- +460 Volt pulse output to coil"
and from this post I quote Grady Clay for the 14pin pinout
"1) Starter – yellow
2) Oil pressure switch – green
3) Oil temp sender – black
4) Oil pressure sender – green/red stripe
5) Power to back-up light switch – green/yellow stripe
6) To back-up lights from switch – gray
7) MFI temperature-time switch – red/black stripe
8) MFI throttle microswitch – gray/red stripe
9) Tach connection to ignition points – black/purple stripe
10) Ignition coil to “intermediate unit” (signal conditioning
for tach) – blue with yellow stripe
11) D+/61 from alternator to voltage regulator – blue
12) Ground from D- at alternator – brown
13) DF from alternator to voltage regulator – black
14) Battery via alternator to fuse #3 – red"

What do I need from the 3.0 wiring harness? I have the 6pin cd box. I have the wiring on the engine that includes a 14pin female connector and a 6pin female connector. Do I need anything different besides the cd box from this picture?

Ken

[jpnovak]

Ken, To make this work you will need the 6 pin CD unit and the complete engine wiring harness from your 3.0.

As mentioned above the 78 SC dist will be triggered by a completely different signal than the 71. The 3 pin box will not read this signal. The wires that feed the 6 pin box are part of the engine wiring harness and come off as a separate lead. In addition all the power leads for the CIS come from this extra harness lead.

There is one way to make this work since you don't seem to have the 78 wiring. You can convert the magnetic pickup to a Crane optical system and trigger your 3 pin box or other aftermarket ignition. This is what I did on my engine.

Here are the pinouts for the engine wiring harness.

71 console side 78 SC engine side final
pin # wire color function
1 Yellow starter yellow
2 Green Oil temp switch Gn/white optional oil press switch
3 Black oil temp Bk/Grn oil temp
4 Gray/red oiil press Grn/red oil press
5 Green/yellow Reverse light Yell/green own wire harness
6 Gray/red reverse light Grey/Red own wire harness
7 Red/black MFI cold start Open
8 Grey/red MFI speed switch open
9 Black/purple dist. Trigger blk/pur dist. Trigger
10 blank blank
11 Blue Alt (D+/61 Blue
12 Brown alt gnd (DF) not connected external VR clip
13 Black alt D- not connected external VR clip
14 Red 12V alt (B+) red


HMM the bbs will not keep the spreadsheet format. PM me an email and I will send you the spreadsheet.

[jpnovak]

Let's try a screen shot.

[K.B.]

Originally posted by jpnovak
..... and the complete engine wiring harness from your 3.0.....

Thanks jpnovak. I'm just not sure what "the complete wiring harness" is. I have the 6pin cdbox and what is normally left on the engine when it is dropped. The wiring harness on the engine that is on the dizzy side has a 14pin, 6pin, 2pin, and 3 loose/cut wires(blue/brown/black). Another wad of wires goes up front incl the CIS stuff. I have another pelicanite who can furnish what else I need If I knew what it exactly was. I just don't know if this puzzle is missing any pieces or not?

Ken

[jpnovak]

It sounds like you have all the wiring you need. The 14pin is the main wiring harness. The 6 pin if 3x2 probably fits your 6 pin CDI. The 3 cut wires are for an external voltage regulator. I am not sure of the 2pin unless you can give a wire color. If its a small connector it might go to the distributor. this will also have a green wire to it. It might have also come off one of the CIS components. There are several. I eliminated all of the CIS connections since I installed webers.

[K.B.]

The 2pin has a red and brown wire. Heres a thousand words on the wires I now have.

[Early_S_Man]

KB,

The 6-pin connector is for CDI unit, 2-pin Red and Brown is power supply for CDI ... coming directly from fuse block on the electrical panel.

The other end of the engine wiring harness is important, specifically the condition of the Green coax cable that carries the distributor trigger signal. If it has turned brown or is cracked ... the short pigtail that connects directly to the pickup coil in the distributor will need to be replaced ~ $30 from Pelican.

A pic of the other portion of the engine harness would be useful ...

The 14-pin chart Jamie has provided and referenced is for the forward '71 [2nd 14-pin] connector, not the engine harness 14-pin connector! Cars after '74 only had one 14-pin connector to the engine harness ...

I don't think you will need to make any changes in the engine harness itself, but there may be some minor needed changes to the electrical panel side of the 14-pin connector.

[K.B.]

The other portion of the engine harness
1,2,3,4 are for CIS
5 red/wht and brn
6 yellow and brn
7 yellow and brn
8 yellow
9 red
10 yellow
11 grey/wht

[Early_S_Man]

8, 9, & 10 are for starter.

11 is probably for oil pressure lamp switch.

6 is probably for the Thermo-Time Switch.

Any other wires offpage to the right of that last pic ... that show green???

edit ... well, there's the green coax to the distributor!

[K.B.]

Besides the spark plug wires and the oil pressures sensor wires on the other side this is it.