'66 Corsa Ignition Problem, Need Help Identifying Wires

[bbodie52]

I have owned 10 Corvairs over the years and have driven them since the 1960's. I have never seen oil consumption like you describe. If there is no apparent leak, it has to be going through a cylinder and out the exhaust — either a faulty valve guide or a bad oil control piston ring. A bad oil control ring would not show up in a compression test. Does any one spark plug show oil contamination? Other than a spark plug showing oil contamination, a bad cylinder wall or broken/faulty oil control ring is hard to test for — short of disassembly and a physical inspection which might reveal the cause. Does the exhaust pipe show a sooty oil contamination? If it does, perhaps removing the exhaust manifolds would reveal the source, with one exhaust tube showing oil contamination and pointing to that cylinder as the source.

Oil Fouled.jpg (208.65 KiB) Viewed 751 times

[rhscholz]

Brad, thank you for your response; I appreciate this. #2 cylinder has the lowest compression reading (130 psi), AND it has the spark plug with
the sootiest/oily contamination, so I suspect that is the cylinder with the highest oil consumption. I am attaching a picture of all the spark plugs,
the way they looked when removed from their cylinders (#1 is lower right, #2 lower left, #3 middle right, #4 middle right, etc.

[bbodie52]

Actually, to my eye, plug #4 looks to be possibly more oil-fouled. A faulty oil-control ring would not necessarily be reflected in the compression test results, but the presence of an oil buildup in the cylinder might cause a better seal and form a higher compression test reading as a result. The high reading of 190 on cylinder #4 could be the result of a heavy oil coating deposit buildup on the rings, cylinder and piston, which could reduce the leakdown and blowby into the crankcase from cylinder #4.

Perhaps others in the Forum who have more experience in matters like this could chime in and provide their opinions.

[rhscholz]

Thank you, Brad, for your comments; I was wondering why the #4 cylinder had such a high compression. Interestingly, none of the plugs really have
the typical oil fouled appearance; they look more carboned up which could be to the original bucking/missing problem, i.e. I was never able to
to put a continuous high load on the engine. I will continue to drive it and watch the oil level, plus any contamination inside the air filter due to
high blowby.

Now I have a new electrical problem : my LEFT REAR brake light does not work. Left rear turn signal works, likewise left rear tail light and left hand
back up light. This is a new tail lamp socket and a new 1157 bulb. All lights on the right tail side work as they should.
I am wondering whether the turn signal switch internally is only connecting the 20 DG wire (right brake light) with the 20W wire from the stop
switch, but not the 20 B/Y wire (left brake light). I jiggled the turn signal lever while pressing on the brake pedal, but this did not make the left
brake light on. Am i on the right track ?

[bbodie52]

The wiring connection from the turn signal switch to the bright filament of the 1157 bulb is the same for both the turn signal and the brake lamp. The fact that the turn left rear turn signal works OK but the brake lamp does not illuminate would seem to indicate a faulty turn signal switch internal contact.

The brake light power feed is a single wire from the brake pedal switch that is applied to the turn signal switch. The turn signal switch (when in neutral with the turn signals OFF) should provide "pass thru" connectivity from the brake light switch at the brake pedal to BOTH rear 1157 bulbs (the brighter filament). When the left or right turn signal is activated, the turn signal switch temporarily disconnects the power source (brake pedal switch) on the selected turn side and connects it to the output of the turn signal flasher (in the fuse block). This on/off switching voltage is applied to the front and rear 1157 bulbs on the selected side, and to the instrument panel turn indicator bulb on the same side.

Since both turn signal lights work when applying the turn signals, connectivity is proven from the turn signal switch to both rear 1157 bulbs. The same wiring segments from the turn signal switch steering column connector remains unchanged when activating the brake lights. Only the power source changes (to the brake pedal switch). Since the flasher voltage is present in the front lights and at the instrument panel, connectivity between the flasher and the turn signal switch is also proven. The only point of interruption that would prevent the rear brake light from working under these circumstances would have to be a faulty internal contact within the turn signal switch.

http://www.corvair.com/user-cgi/catalog ... IN&page=87


Part number C862: 65-66 & 64-65 FC DIRECTIONAL SWITCH

Weight: 1 lbs 0 oz
Catalog Pages(s): 87
Price: $ 60.50

[rhscholz]

Many thanks for your comprehensive explanations (as usual), I really appreciate this ! I am glad you are confirming my initial
analysis that the turn signal switch is probably the culprit; I will order a new one from Clark's Corvair. Wishing you a Happy Thanksgiving
with your family, and again may thanks for your support.

[bbodie52]

If you like, you could unplug the existing turn signal switch connectors on the steering column, and use a multimeter to check for continuity between the terminals — using the wire color codes as your guide. The wire color codes are 20 DG for the right rear, and 20 B/Y for the left rear. The color code for the stop lamp switch (brake light power source) is 20 B/W. The wire that brings power from the turn signal flasher is marked 18 PPL. With the turn signal switch off (neutral) you should be able to measure continuity through the switch between the brake light power source (20 B/W) and the right rear (20 DG) and left rear (20 B/Y). If the switch is faulty the last test will likely fail. Moving the turn signal switch to left should show continuity between the left wire and the turn signal flasher wire (18 PPL) and the left rear (20 B/W). Finally moving the turn signal to the right should display continuity between the flasher wire and the right rear (20 DG).

[rhscholz]

Brad, many thanks for your help ! I will do some troubleshooting with my DMM to confirm that it is the turn signal switch mechanism.
Looking at its internal design, it is amazing that this simple, but elegant design lasted 50 years in my car !