66 turn signal problem

[Tom C.]

Just finished rewiring my 66 Coupe with new front and under dash harnesses. I gotta say right here that I'm pretty darn proud of myself, because I've never done a project on a car quite this involved. it looks real pretty and I don't have any short circuits, and everything works with one exception, turn signals. I'll start with what IS working in the turn signal system.

1. I have a rt turn signal indication on the cluster and a rt turn signal on the rt tail light and rt parking light.
2. I have headlights and tail lights all around, the only exception being no high beam headlight on the left front. (probably the lamp).
3. I have both brake lights and a rt turn signal with the brakes on (rt turn selected)

WHAT I DO NOT HAVE:

1. No left turn signal on the cluster but the left turn signal works on the left tail light
2. No left turn signal on the left front parking light, whether the parking light is on or off.

Questions: where should I start troubleshooting first? Is it possible that this is a turn signal switch problem? Flasher problem? And another unrelated question. My parking lights are on in the parking light position on the light switch, but when I switch on the headlights, the parking lights extinguish. Is this normal?

I should add that the wiring harness on the steering column is original, but the under dash (dual plug) connection is of course new.


Thanks in Advance for any troubleshooting suggestions you all may have, hopefully starting with the easiest first.

[Stephen L.]

Re: 66 turn signal problem

The flasher is common to both rt & lt turn signals so that rules that out.
I believe in 1966 the parking lights (front) are NOT on with the headlights. (That started in 1967)

I would replace/transfer the front parking light bulbs, side to side to see if the problem "follows" the bulb. Replace as necessary.
If these steps correct the external light problems then you probably have a faulty bulb in the left indicator position. Install a known good bulb to see if the problem persists. Replace as necessary. If that does NOT solve the problem then you may have a faulty wire or socket in the harness.....
Will all signal lights work as well as the cluster lights. If they do then the bulbs are good and the turn signal switch would be suspect......

[Edward J.]

Re: 66 turn signal problem

Tom, I approach the problem by starting with the easy stuff, bulb as Steve says, then wiggling the connections, start by turning on the left turn and try the connection at the inner wheel well, firewall, and then the directional switch under the column, also do a visual look and make sure no terminals were pushed out of the sockets when plugging harness together. this only take a few minutes, next take a test light and check power at the harness under inner wheel well. should have power at one terminal and black should be ground.

[Randy R.]

Re: 66 turn signal problem

On my 67 I traced a turn signal problem to the steering column junction block (The curved one at the bottom of the steering column). One of the wires coming from the column was not pushed in all the way.
Good luck,
Randy

[Tom C.]

Re: 66 turn signal problem

On my 67 I traced a turn signal problem to the steering column junction block (The curved one at the bottom of the steering column). One of the wires coming from the column was not pushed in all the way.
Good luck,
Randy

Thanks very much. I'm pretty sure the problem is somewhere in the wiring between the turn signal switch and the harness that goes to the front parking lights. Both parking lights DO work when I turn them on, so I don't think it's a bulb problem as the bulb only has one element.

Thanks again to all

[Bob R.]

Re: 66 turn signal problem

You didn't mention the condition of the directional lights before you replaced the wiring did it work then. Those parking light bulbs have two filaments in them one for the running lights and one for the directional only.

[Tom C.]

Re: 66 turn signal problem

Oops...didn't know that there were two filaments. The parking light harnesses are new and they came with the bulbs installed (Paragon). I will check the bulb first, since that is the easiest of all worlds to check. Next, I will be checking power to the light blue leads at the column harness. I know it's possible that there is a connection problem there as the column harness is original. Last but not least, I'll have to tear into the column and check the turn signal contacts. Found these photos on the internet.

[Ed S.]

Re: 66 turn signal problem

I have a question regarding the 3 small metal "springs" in the picture above. This pic is a representation of a '66 turn signal. Can anyone confirm that the position of the 3 small metal springs are the same in a 64 turn signal connector housing? I pulled my turn signal components today - it was not holding in one direction or cancelling in the other. As I was disconnecting the plug 2 of the clips "popped" out - before I could see how they were supposed to be situated. If the 66 arrangement is not the same as the 64 can someone post a pic of the correct arrangement. Thank you.