red66bb

Hi
New to corvettes but not new to cars.

I have searched the forum and looked at the TI ign threads but could not find exactly what I needed. The car is mostly stock but the PO decided to replace the TI system with a points system. I have all the parts to restore the car to TI ignition. I'm using a new M&H TI harness, rebuilt amp box and distributor.

I am trying to connect up the TI harness to the main harness.

Questions:

1
One of the two pink wires coming from the driver side dash area go to an "L" shaped connector along with a green wire. The other pink wire had a poor splice going to the coil. The diagrams indicates these should be 12ga wires, however they don't appear that thick. Should the single pink wire connect to the white resistor wire in the TI harness?
I have a photo showing these wires-


2
There is a pink wire coming out of the wiring harness over the wiper motor. The wiring diagram shows a TI harness connection to the starter. Is this the proper connection to the pink TI harness wire as shown in photo?


Thanks for your help

Velox

Well for the first question the pink and green pair of wires going to the L connector are for the backup light switch, they have nothing to do with TI, and if you find the wiring connector from your backup switch down on the transmission reverse linkage, you will see that connector exactly fits the L connector on the pink/green pair you mention. Dr. Rebuild has an excellent wiring diagram available, it shows all the wiring in color and exact pictures of the connectors, and the 66 ignition harness section includes a TI discussion.

Critter1

The pink wire that's spliced into the black wire is the feed coming from the ignition switch. The pink section (without the black spliced section) should have a connector and plug into the white resistance wire of the new TI harness. You will need to add a new connector to this pink wire.

The pink and green wires in the "L" shaped connector are supposed to go down to the back-up light switch on the transmission.

Velox

And another tip, when using a correct TI distributor, the TI distributor wires may both be white, or light tan, or gray, or one may be green, but for sure only one of them is green or has a green tracer. Those wires have a very specific orientation into the distributor connector that fits to the TI harness connector, see photo. I learned this the hard way...

Critter1

Here's a pic of the pink wire connected to the white resistance wire of the new TI harness. You will need a spade terminal on the pink wire and a plastic connector.

red66bb

thanks all


Now, how about the pink wire over wiper motor??? Is that the correct one for the TI harness pink wire?


I had the "L" connector for back up lights identified. I needed verification the single pink spliced into the black was the correct wire for the TI harness white wire.
I actually have the other half of the pink wire with the original connector. It was attached to the ballast. That is now properly re-attached together.
So that's sorted...


I appreciate all the help and I always appreciate info from those who have gone before me...

DansYellow66

Go down to about post 15 by Rich5962 in this thread and you will probably find about everything you need to know on hooking up the TI harness.
https://www.corvetteforum.com/forums...-ti-parts.html

red66bb

Dan,


Thank you, I have read that post in its entirety.


Although helpful, the post did not help me the find the engine harness pink wire connector to the starter relay or verify the connector I photographed is the correct connector to the TI harness and relay.


I am hoping a fellow 66 big block owner can look at the connector location over the wiper motor and see if the TI harness pink wire connector plugs in to it.


I am trying to be careful and not fry the parts.


Thank you for the help.

rich5962

The Pink wire you're looking for is likely inside the stock forward engine harness over the wiper motor and may have been cut by someone in the past. I would carefully open the harness over the wiper motor area to try to find it. But first, I would check that the starter solenoid has a Pink wire on it's "R" terminal, or it may be hanging there in the air. If it's there, then you'll have to open the harness above the wiper to try to find it.

Just to clarify a few things......

In your 2nd photo above, the Pink wire with the connector on the end and which ties into the distributor connector, I see is your new TI harness. The single connector end in your photo will connect to the starter solenoid "R" terminal, when you find it of course. This is to supply full battery voltage during crank to the TI module AND the Distributor Pickup Coil. In a Points standard ignition, that Pink from the "R" terminal goes to Coil+, along with the Ballast output wire, a larger gauge Pink.

For TI conversion, in my photo from the linked post(again below), you can see the long Pink wire on the center/left of the image, then it connects to the distributor connector in the lower right. The tape on that wire is marked "cut from original coil+ wire". This is the Pink wire you're looking for.


Points ignition systems have a larger Gauge Pink wire(Ballast Output) tied to the smaller gauge Pink wire going to the "R" terminal, and both go to Coil+, but on Points ignition only. What is done in a conversion to TI, is that the large gauge Pink wire is cut free from the small gauge Pink U shaped terminal(coil+). The large gauge Pink is then removed in it's entirety from the forward harness.

Also note that the GM Wiring diagram states that wire is Yellow for 1966 to 1971. It's not Yellow for the C2's, only for the C3's as I recall.

buns

There are no 12 gauge pink wires in the factory ignition harness. 18 gauge only.






This is what the harness connections look like.









Here is a diagram I made showing the schematics.

rich5962

Tim, Very nice photos and diagrams.

I see now 1966 had all #18G. The TI Wiring diagram above is confusing as it shows 12G Pink at the IGN switch. A 1967 harness uses #12G from IGN switch to Ballast, and Ballast to Coil+. My references were 1967.

Rich

red66bb

Rich and Buns,


Thank you for the info.


Several people told me, including the person who rebuilt my distributor, to look for the 12GA pink wire. The wiring diagrams showed 12GA ignition wire also.


My car is an original TI car with the original main harness so I was concerned about no 12GA pink wire from the ignition. I have done enough wiring in everything from early minis to factory race Porsches to know that an undersized wire is not a good thing in most all cases. Thanks for verifying the 18GA wire is correct for the 66 TI ignition system.


So all I have to do is splice the end I found attached to the ballast back to the 18GA pink ignition wire stub. They are a perfect match and no doubt the factory set up. Sorted.....


My harness does have the connector between the TI harness and the starter relay and can be seen (although not real clear) in the second photo. I can't verify the starter end, as the car is currently nested between two other cars and I can get my jack in there to lift it. But it all looks good that it is the correct TI connector location.


When I get it all up and running I take some good photos and write short wiring summary so the next person can sort it out for a 66 BB.


Thanks to all who helped me.


PS
My next investigation is why my back up lights work even though the green/pink connector to the back up lights is not connected to anything. I love a mystery and old cars.....

Critter1

I'm not 100% sure but I think 66 used 18G pink wire from the ignition switch while 67 used a heavier ga wire, probably the 12G that you mentioned.

I know my 66 has 18G pink from the ign switch.

DansYellow66

Someone probably didn't understand the wiring and ran a hot wire to the switch on the transmission and a ground to the frame - that would be my guess. If you have any extraneous hot leads out of the fuse box or strange splices that may be why.

red66bb

Update:
The pink wire single female connector over the wiper is the correct connector to the starter relay post. sorted....


I looked at the wires in the starter area and they were ran on top starter near the exhaust manifold so they were cracked and brittle. This lead to rebuilding the lower harness. sorted...


The single 18GA pink wire next to the double green/pink backup light was spliced back to the original connector.. sorted


When putting rebuilt TI distributor in the number one plug terminal location did not match the "66-67" diagrams. After a long research trail, finally looked in my 66 L72 assembly guide and viola the diagram and my distributor looked the same. I made a cap that I could see the rotor. It looked right. Put the real cap back on, crossed my fingers and fired the engine up..
Adjusted the timing and it ran perfectly!


Test drive yesterday: smother than before, acceleration better, idle was steady. all good.


Next: new 3742 carb install


Thank you to all who helped.

DansYellow66

Thanks for reporting back. I put a correct TI system back on my car a few years ago after running an Accell CD unit through the original TI distributor for years. I was also very surprised how quickly my car starts and noticed an improvement in overall performance. My plugs don't seem to need dusting off with a burst of acceleration nearly as much as they used to. It could be the modern TI internals but overall it just seems like a very good system.