1967 Corvair wiring problem

[KulasO313]

Hi everyone,
Quick question. I just put a motor in my project 67 corvair 500, and am curious as to whether or not the wiring harness is different in a 67 than it is in a 65. I have a pdf wiring diagram of the 1965 shop manual that lists the wires and their colors, but unless im reading the sketch wrong, the colors dont really match what I have. I have an alternator on the car which i believe I have hooked up correctly. Outside of the wires from the alternator, which wires go to the voltage regulator? A thick purple wire and a skinny yellow wire, which I have read go to the starter, were run into a plug that had no where to plug into. I cut them and ran them to the starter. There is also a thicker red wire in the junction that I am unsure as to where it goes....the junction im referring to is of course the rear harness near the motor. hmm, guess this wasnt that quick of a question. Bottom line is im pretty lost right now and this car was sort of a basket case and I cant seem to get power to the ignition at all. So is there a difference between 67 and 65? Or am i reading the 65 shop manual incorrectly? If there is a difference, does anyone have a pdf of a wiring diagram for 67? thanks so much as always. Id love to finally get to drive this car.

--Nick

[UNSAFE]

I think most of the wire connections are the same in 65 -67.

The regulator wires should be connected to a plug that fits the regulator terminals . It is common to most GM cars from the era and may even be a FLAPS part .

The purple and yellow go to the starter . The purple wire is the one that makes the starter turn . I think the yellow is ignition bypass ????

The large red pigtail goes to the battery plus side .

A photo or two of what you have or don't have may help .

[bbodie52]

Here are the schematic and wiring illustrations I have for the 1965 Corvair, to use as a baseline...

Note that the engine compartment JUNCTION POINT (10 Gauge Red) is a voltage tie point between the alternator power output, battery power positive terminal, and the primary power feed line that runs to the passenger compartment, fuse block, etc. All power for every accessory, lighting, horn, heater fan, wipers, ignition system, etc. passes through this junction. The only exception is the direct 6 Gauge cable that runs from the battery positive terminal to the starter solenoid. This connection provides a high-current path that powers the solenoid and the starter motor, and through the solenoid provides a full 12V DC temporary feed to the ignition coil positive terminal to boost ignition spark voltage during periods when the solenoid is engaged and engine is being cranked by the starter. This "hotter" spark voltage enhances engine starting. The voltage shuts off when the key is released and the starter is disengaged — leaving a lower 6-7V DC via the ignition coil resistor circuit that is present as long as the key is in the ON position.

Note also that for every POSITIVE power connection, a comparable corresponding NEGATIVE GROUND connection must exist. The wire gauge for these GROUND connections must be equal to or exceed the wire gauge of the positive feed, to provide a comparable GROUND RETURN PATH. For this reason the thick 6 Gauge black negative battery terminal cable is bolted directly to the engine, so that the starter motor has a ground return path that is equal to the gauge of the positive battery cable. The 10 Gauge NEGATIVE GROUND wire is fastened to the chassis (frame) ground, and is equal to the 10 gauge positive wire that powers all of the car lights and accessories. (The schematic diagram shows a slightly thinner 12 Gauge Red and a 12 Gauge Black wire tie to the POSITIVE JUNCTION and CHASSIS GROUND. This is acceptible because of the short length of these cables. The wire current carying capacity is a function of both the wire gauge (thickness) and its length. Since these wires are short, the engineers deemed the thinner 12 Gauge to be acceptable between the battery and the connection points. The longer run between the alternator and the harness behind the instrument panel receives a thicker 10 Gauge wire.

Left-click on the image to enlarge for better viewing...

1965-1969 Corvair Engine Compartment Wiring Diagram

1965-1969 Corvair Engine Compartment Wiring Harness Multi-pin Connector

1965-1969 Corvair Engine Compartment Wiring Harness Multi-pin Connector.jpg (33.79 KiB) Viewed 2529 times

1965-1969 Corvair Engine Compartment Wiring Harness Starter Connections

1965-1969 Corvair Engine Compartment Wiring Harness Starter Connections.jpg (80.88 KiB) Viewed 2529 times

1965-1969 Corvair Engine Compartment Wiring Harness

1965-1969 Corvair - Instrument Cluster and Body Harness

1965-1969 Corvair Engine Compartment Wiring Harness

1965-1969 Corvair Trunk Schematic Diagram

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This is the only 1967 Corvair wiring diagram I could find on the Web to display here for comparison with the 1965 diagrams. There are others available for purchase elsewhere in the 1967 Chassis Shop Manual Supplement and from other sources.


1967 Chevrolet Corvair Color Wiring Diagram

[KulasO313]

Thanks very much for the info. I found that the red ignition wire had power in the back but up front under the dash it had nothing. I believe I have just about everything hooked up correctly at this point but I still have some troubles. I jumped the red wire and have power to the switch now. When I turn the key I get power right at the starter via the purple wire, but the car does not crank at all and I still have no head lights...sounds like a ground issue to me. I ended up grounding the neg cable to the exhaust manifold as its the only steel I can find on the motor. Should I add another ground? Also, does the resistance wire hook up to anything in the back? Thanks guys for any info. I'm
Close, I can smell it.

[bbodie52]

The normal ground point at the engine is to the left of the alternator. There is usually a support brace bolted to the alternator, and the other end of the brace bolts to the left cylinder head. This is usually the ground point for the thick (6 gauge) battery cable. You can see this cable in the above picture.

Since the engine is suspended by three rubber engine mounts, the mounts do not provide a ground path. The LM engines usually have several small braided ground straps to ground the corners of the sheet metal to the chassis (seen in the above picture on the right). But the high-current starter motor needs a good ground return. That is why the main negative ground cable is bolted to the left cylinder head near the alternator.

That engine ground is not sufficient for the chassis ground, that provides a ground return path for all of the accessories, horn, lights, etc. That is why a second ground wire (10-12 gauge) is connected between the negative battery terminal and the car chassis, usually at a bolt near the battery in the perimeter chassis engine compartment frame.

[KulasO313]

Thank you VERY much for the help. Part of my problem was the battery (which is not that old), had a short in it. So it had juice when I checked wires but when I would turn anything on, it would drain immediately. I got the motor fired up for a split second last night (with starting fluid), but still have to hook up carb linkage and fuel line. Any PDF or pics of how these vacuum lines are supposed to go? I'm going to use individual aftermarket air cleaners because my stock cleaner is junk. Thanks again for all the help.

[KulasO313]

Oh and it's a 2 carb motor

[bbodie52]

I cobbled this generic diagram up to illustrate vacuum connections in a variety of Corvair configurations.

This diagram illustrates potential problem areas for a normally aspirated Corvair where vacuum leaks can occur.



The PCV tube seen on 1963-1969 Corvairs uses either a fixed orifice or a PCV valve to connect to the vacuum balance tube. The other portion of this tube connects to the air cleaner. The crankcase is sealed, and vents through these two connections. Both the vacuum path and the air cleaner path function at different times, depending on the speed and operating condition of the engine. The upper PCV connection can be fitted with its own small air filter to keep dirt out of the crankcase. But the idea is to recycle crankcase blowby fumes back through the carburetor, either through the vacuum intake connected at the carburetor base, or through the upper intake where crankcase fumes are drawn through the air cleaner assembly. If possible, the upper connection should be connected using tubing to one of the air filters attached to one of the carburetors.

Early Corvair PCV System

Early Corvair PCV System.jpg (43.83 KiB) Viewed 2472 times