08hybridok

So I'm helping sis-in-law with her 67 convertible.

I changed the master cylender the other day, and not sure if it's related; but noticed today when holding the brake peddal dow as far as it'd go, the dash lights would flicker, and saw sparks/smoke come from where the steering column meets the fire wall.
It wouldn't do it every time I mashed the pedal, nor just holding it part way.
So I poke my head under there, can't see anything obvious.
But then just moving the steering column (like putting pressure on it in various angles would make it spark too, as does using the tilt wheel, and the tilt away thingy. So basicly any stong/firm movement.

Where should I begin looking? Could it simply be the brake switch? (are there multile ways to install it & it still work, ie light up when its supposed to)

I don't recall the turn signals in the hood working pre- brake job, but now they are. I might have just missed it before.

This is happening key off.

Any suggestions ???

barstowpo

Disconnect the battery asap. Look for chafed wires from the TS switch inside the column. Also look for a loose/broken fuse block. It is under there near the column. Also look for melted or frayed wires coming out of the fuse block or in the main bundle. I hate wiring. Good luck.

08hybridok

Thanks; battery disconnected. Turn sign was on my to do list, there's a new cam waiting to be installed (left works, right won't latch/stay on)
I didn't see any obvious signs of fray, bare wires, but the only spark I see is at the firewall itself, not near any wires!
I assume something is putting positive on the column shaft, and when it touches the firewall, zap.

fastbackford351

If this all started after you installed the master cylinder, make sure you didn't pinch any wires or jostle any splices loose during the swap.

What kind of shape is your wiring harness in, in general? Is it pretty much intact or has it been hacked, whacked, spliced and diced for the last 50 years?

If you're getting enough juice to ground to cause smoke then you should be able to pick up the signal with a test light. So, stand on your head and really start going through with a fine tooth comb, the under the dash wiring.


protip from a rank amateur: If you're going to be under the dash for any length of time, pull the drivers seat out because once you reach a certain age/girth, diving under the dash gets uncomfortable as hell and any extra room you can find is well worth the 10 minutes it take to pull the seat out.

bop11

One other area is the horn. Did you change the steering wheel? The horn button is not a ground button but a switch in the 12 volts to the horn. Some after market steering wheels have a spring clip that holds the horn button. Unless it is modified, it can touch the steering column. This causes problems in original steering columns because the column is grounded. If you insulated the new column when you installed with rubber mounts, it may be touching some part of the pedal or firewall when you put pressure on it or move it around.

08hybridok

She did replace the steering with a replica a few years ago. She doesn't drive much so it could be related.
So no real way of knowing if I broke it, or it was already broken... will take much investigating into it.
Thanks for the leads!

08hybridok

Actually is there an easy way to disconnect the horn/voltage going into the steering wheel to make process of elimination easier?

fastbackford351

There is a connector coming from the column to the rest of the harness.

08hybridok

Thanks, I took the wheel off anyway to change the signal cam. With it dangling in the air, pushing the column around, no sparks. Push brake pedal, no sparks.

Going to rewire the new cam and see what happens.

2 new questions. Is the big center cap thingy a horn also? Or should it be insulated?
Does this new part just screw into the plastic black piece inside here?

fastbackford351

The emergency flasher know goes right where the old one came out of.

What kind of steering wheel are you working with? Is that the back side of the Cuisinart looking center piece of a factory 67 wheel?

Pics?