Alternator/Wiring harness help

[Ayles]

I am inching ever so close to the point of being able to put my engine in. Came to a slight issue last night while trying to put my engine wiring harness in.

My car is an 82 911 SC, I got it as a roller with no engine. The engine I have came without a car, thus no wiring harness. I was given what is said to be an RS Harness. Thought this would work since it's a carb conversion and I didn't need any of the CIS stuff. The harness is in beautiful condition and very well built but appears to be missing one thing. Per the Bentley manual there are several connections at the alternator. A couple screw down terminals and a two way plug. My wiring harness (the portion that goes into the fan shroud) only has two wires with ring terminals on the end. A heavy red wire and yellow and missing the plug.

I do have a 914-6 harness I could use but it's got a ton of additional crap dangling from it so not ideal.

[mreid]

Those wires go to the starter - heavy red from alternator output to battery lug on starter and yellow from 14 pin connector, through engine harness to starter solenoid.

Do you have an internally regulated alternator? If so, your engine harness should have a heavy red, light gauge blue, and brown (ground).

[Ayles]

Thanks for the comment, I think posting a few pics of the harness and alternator would be helpful. I will take a couple tonight and add them to the thread.

[E Sully]

Contact Dennis, user name Timmy2. He can help you out.
Building SC and Mid Year Engine Harnesses

[timmy2]

Post up some pictures and I can fill in the blanks for you.


Sent from my iPhone using Tapatalk

[Ayles]

Here are the pics they will move right to left along the harness. Also, I definitely made an error in my first post. The portion that would go into the fan shroud are Red and Blue.

[Ayles]

And a pic of the alternator:

[mreid]

Your harness is set up for internally regulated alternator. Here's what I see looking at your harness right to left:

Back up light tranny connector
Starter (red to large battery lug and yellow to solenoid)
Rubber insulator that clips into front engine tin cut out
Oil temp
Alternator (red to B+ and blue to exciter)
I can't really see the others, but one is the oil pressure. Dennis will know them all.

[timmy2]

As above your harness is built for carbs, but for an internally regulated alternator. Looks to be plug and play for a carb engine.

The alternator you have is older (like '70 or so) and will not work without an external voltage regulator.

Updating to the correct alternator is what I would suggest as otherwise the harness would need to be re-wired and you would need to buy a remote VR.



Sent from my iPhone using Tapatalk

[timmy2]

Moving from left to right in the picture of the entire harness:
6 pin CDI connector. T connector for CDI power and safety switch for fuel pump (deleted).
14 pin connector.
(Branching off) Distributor plug, coil wires and the 2 wires that go to oil pressure sender and temp sender.
(Next branch) alternator wires blue & red.

Then green white to oil pressure idiot light sender,.
red and yellow to starter, then finally the reverse switch connectors.


Sent from my iPhone using Tapatalk

[Ayles]

Edited... Missed one of Timmy2's posts.

Thanks!

[boyt911sc]

From what I could see from these pictures:

2nd picture:
14-pin connector (engine side)
White plastic connector is T14/10 coming from the FP relay @terminal #30
6-pin connector for CDI

3rd picture:
big green wire goes to ignition distributor
eyelet terminals go ignition coil
green (small) goes to oil pressure sender
the other wire (?) to oil temp. sender
big red wire goes to alternator @ B+
blue wire goes to alternator @ D+

4th picture:
gree/brn (?) goes to oil pressure switch
big red wire goes to starter @terminal #30
yellow wire goes to solenoid @terminal #50

5th picture:
back-up switch (reverse sw) at transmission nose.

Tony

[Ayles]

Looks like new alternator it is! I have loved buying parts but for some reason this strikes me as less fun than the others.

I have read a few threads on alternators and it sounds like not all of them are plug and play. Any ideas what alternator I should be looking at?

[mysocal911]

Originally Posted by Ayles

Looks like new alternator it is! I have loved buying parts but for some reason this strikes me as less fun than the others.

I have read a few threads on alternators and it sounds like not all of them are plug and play. Any ideas what alternator I should be looking at?

The alternator shown in one of the pictures is a Bosch 55 amp used in 911s prior
to the 911SC. It's key that any other alternator used be compatible with your present
alternator housing, i.e. later alternators require deeper housings. Check the Pelican
Parts catalog or call a Pelican Parts sales person for a replacement.

[Ayles]

Thanks!! I will shoot them a call tomorrow.

[timmy2]

As I posted in your other thread about the missing oil pressure gauge, it would be worthwhile to determine your engine year and type before trying to order parts.
Post a few pictures of it from different viewpoints as well.

EDIT
Just saw your post on the year. 1980 ROW engine
it appears you are missing the block and sender that are usually there.

[timmy2]

I would pull the fan strap and look at the numbers on the fan housing to determine what alternator will fit. The guys at Pelican should be able to find the right one.
(I'm guessing it may have been changed along with the alternator)...

[Ayles]

Ahh good call! Didn't even think to note that. I will jot that down.

I have zero history on my chassis and some limited history on my engine.

[Ayles]

The help line at Pelican didn't have a way to cross reference the shroud and alternator. If I want to stay with what I know fits then this should be the model I buy, seems to match what I already have if indeed its an older 55amp unit:

Alternator

[Ayles]

Got my new alternator almost installed and come to find out the cup washer is large enough as the new alternator takes a 24mm nut. Pelican carries only one size from 65 to 89.

The inside diameter of the old one is 14mm the new one would need to be 16mm to fit over the shaft. Is it a problem to open up this hole with a dremel? Someone has to have had this problem before...