Electrical: wiring headache

[Yogi]

We put in a new wiring harness on my 1960 Hawk. Got most all of the gremlins subdued except one concerning turn signals. Passenger side turn signals work fine. Drivers side works fine until you turn on the headlights. With headlights on the turn signals burn but will not blink. Headlights off, they work fine. Does any one have any idea what we did wrong?
All help appreciated, Yogi

[skyway]

Grounding issue?

[rkapteyn]

Take a voltmeter and check if the voltage drops a lot when you turn on your headlights
The blinkers need full voltage.
Does this happen with the engine running or not running.

[gordr]

Odds are you have a bad ground at one corner of the car. What does it do when park lamps only are turned on? The park lamps position sends juice to the parking lights, and also the tail and license lights. Headlamp position sends power to the headlamps, tail lamps, and licence plate lamps, and both send power to the instrument lamps. Turn signal failure in both "park" and "headlamp" position, would rule out a bad ground in one of the parking lights. Most likely, you have a bad ground at a tail light. With the lights off, the turn signal to the affected socket finds ground by back-feeding through the dim filament of the affected bulb, and getting ground through the other bulbs in the chain.

Switch ignition to "accessories" operate the turn signals and observe all 4 corners of the car. The corner with the bad ground will flash dimmer than the others, because it is the "dim" filament (park or tail) being flashed, not the bright one.

[altair]

I would suggest to ground each socket with an accessory ground wire while the left turn signal is actuated. If it comes to life that is where your ground is open. Usually it is an operating light that has the open ground and can easily fool you. I one time had a double filament lamp when one filament opened and welded itself across the other filament. It took me a week to find the trouble, when I turned the signals on the dash lights and radio also flashed.

[57studechampion]

I had the same issue when I put new front and rear parking and taillight assemblies in my car. On my Champion there is a grounding block by the hood latch. I had a wire on the wrong terminal. Changed them around and all works well. Good luck

[Rafe Hollister]

I had issues with a rear light. By tester said it was getting power. I added a ground but no difference. So I replaced about 3' of wire and its fine, but my stuff was old, sounds like yours is new. Still, double check wires and connectors. The 'bad ground' is almost always true in my experience, but not this time.
Rafe

[Yogi]

FOUND IT!!! - We were all right, it was a ground issue. The metal bracket that holds the indicator lights, (left-right turn signal and high beam) behind the fiberglass dash was not grounded. Ran a ground wire and now everything is working perfectly. Thought everyone would like to know so they could file it with the other information they will probably never use.
Thanx to all of you for your input. We used all of your suggestions in the process of elimination. Yogi (slightly smarter than the average bear)

[fpstude]

This thread is now filed for future reference as I'll be wiring our '50 in the near future.

[skyway]

Nice work 👍

[Yogi]

Hey Y'all, We're still having wiring problems. I have a question that may help. Should the park lights burn with the headlights on or not? There seems to be a problem one way or another.
Thanx for your input, Yogi

[Topper2011]

Not on my 62 GT. My switch when flipped up, turns on the parking lamps, down turns on the headlamps. Or was is vice versa?

[Skip Lackie]

It did not come from the factory that way, though it's easy to change. Parking lights coming on with the headlights did not start until 1967 or so. Someone correct me if I'm wrong.

[StudeRich]

If you have the Parking lights on with the Toggle UP for Headlights, the Black with Yellow wire to the Parking Lights is on one of the Instrument Light Terminals of the Headlight Switch, it goes on the Parking Light Terminal.

Some people would leave it that way, though not Factory correct.
Is there still another issue that matters, with the Electrical System?