14 pin connector diagram

carrera turbo · 09-21-2008, 01:53 AM

i have a 1975 carrera and just installed a 3.0 engine and harness. what im trying to figure out is what the pin number is on the 75 carrera harness for the tach and the number on the 78 sc i took the motor out of. everything seems to work except the tach. i have swapped out the tach from the sc to make sure it was not a ohms issue and the tach still will not work.

i have done a 20 page search here on pelican and have not had any luck

any help would be great

ed

boyt911sc · boyt911sc's Garage

My computer has crashed and could not retrieve my documents. What particular pin number/s are you interested? I have a hard copy and the description in details for the 14-pin connector. Let us know what you need.

Tony

carrera turbo · 09-21-2008, 08:57 AM

the connector im looking at is the main engine harnes plug. the wires are in different locations and i think i just need to swap one of them around to get the tach to work.
so a diagram for the 1975 2.7 U.S. 911 and one for the 78 SC would work great.

thanks ed

Grady Clay · 09-21-2008, 11:33 AM

Ed,

I assume you have the engine running and everything else works.
On your ’75 chassis the tach connection does not go through the 14-pin connector, it connects to the 3-pin CDI at the T2a connection (2-pin) near the CDI. The two wires there should be a red one and a black/violet (tach/points) one. On your ’75 the wire did continue to the engine points, just not through the 14-pin connector. The CDI has a separate harness.

On the ’78 011SC, the tach is driven from the pin TD of the 6-pin CDI connector. The 3-pin and 6-pin CDIs are different animals. The ’78 911SC does not have ignition points rather has a magnetic pickup.

The simplest solution is to install the 6-pin CDI from the ’78 911SC.

I don’t think the tachs are electronically different between the ’75 and ’78, just calibration and appearance.

Are you sure of the ‘78 year engine wiring harness and 3.0 engine are you putting into your 1975 911 Carrera Targa? Is it original CIS? Any mods or molestation?

I have a ’78 or ’79 911SC 3.0 (possibly 3.2 displacement) engine in a 1974 911S Targa. I can compare the ’75 and ?? year 911SC 14-pin wiring diagrams and confirm with this ’74 car for you. It still has the ’74 tach but has a MSD CDI so I can’t confirm the CDI wiring.

Best,
Grady

NY65912 · 09-21-2008, 01:27 PM

Try this, hope it helps.

Wiring diagram needed - '81 14 pin connector on relay side

boyt911sc · boyt911sc's Garage

The location of the tach wire connection in a 14-pin connector (SC's) is located at #12. This is the the black/purple wire. Do you have the 6-point CDI already? As mentioned earlier, the '75 wiring for the 14-point connector is different for the SC's. Keep us posted.

Tony

carrera turbo · 09-21-2008, 09:13 PM

hey guys thanks alot, i found the wires as indicated by grady. so i installed the 6 pin CDI box when i installed the engine. the missing link was the 2 pin connector that was not getting a signal because it had no feed for the tach.
so i removed the black/violet from the t2 plug and then found the black/violet from the CDI box labeled TD and soldered these togather put the new wire back in the plug wraped them back up in the harness and all is good and the install looks factory

thanks to all that helped just got back from a 125 mile run and it worked great.

thanks Ed