Car = '74 2.0

Well, my last post was premature on this, but I really do have a problem with my turn signal indicator. Here it is:

My signal indicator has never worked. Found no indicator bulbs in the sockets inside the the tach gauge, so I installed the correct 2 watt bulbs. Now, with the key in the on or start position, the indicators are always lit. If you signal left or right they both pulsate. The car's actual blinkers function fine. I now understand why the P.O. removed the indicator bulbs. Any idea why this is happening? Is it in the column switch? Thanks.

Ansbacher

I forget what year the change was but later cars don't have individual blinking bulbs in the gauge anymore, they always blink together.

I think there's a diode in the circuit (was it blue?) that could fail allowing current to flow back, but i also don't remember if that was in the early or late or both.

It's been many years since i had to diagnose any of that ...

Is your tach the early style silver button with L/R arrows, or the later black center?l with one green dot TS indicator?

74 cars had the single bulb TS indicator, the chassis harness was wired that way. If your chassis harness has no factory provision for 2bulbs, a PO either modified it by adding a second bulb in series or you might have the early VIN 74 silver button tach with two factory bulbs. Please clarify what you have.

I just checked the '74 current flow diagram and the chassis harness is missing the two individual grounds that triggered the left/right indicator bulbs on early cars.

So the switch over from individual bulbs in the gauge to just one for both must have been between '73 and '74 somewhere.

The car is an early '74 (build date August 1973) with silver dot gauges. Does this help?
The tach definitely has two bulb sockets at the top for indicator illumination. They look original.

Ansbacher

You’ll need to use the 1973 chassis harness schematic to troubleshoot.

Start with the basics. Fuses, grounds, no corrosion on contacts, including exterior TS housings. Swap the TS relay. Check that your car exactly matches the schematic in every way.

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Well, I got everything working as it would on a pre-74 car with the separate left and right indicator arrows being illuminated independently. All I did was tap into each 12 volt blinker supply voltage lines and run a feed to each of the arrow lamps. Works perfectly and did not affect the actual blinkers or parking lights.

Thanks everyone for suggestions and Andy's schematics.

Ansbacher