WHAT THE HECK IS A…Turn Signal? (because it is apparent that some people don’t know)

Welcome to another edition of “WHAT THE HECK IS A…”! I hope you brought your Poncho of Positivity, because there’s a slight chance of cynicism up in here.


To know what the heck a turn signal IS, we must first explore what the heck a turn signal IS NOT. A turn signal is not:

  1. The thing that will create the beat track to the next hit electronic dance single
  2. A very slow strobe light
  3. The way Gothrum calls Turnman
  4. Something that should be used all willy-nilly

He’s the hero Gothrum deserves.


So…what the heck is it then?

A turn signal is a light on your vehicle that you should activate while driving, and indicates to other drivers which direction you will be moving your vehicle in the immediate future.

How Does It Work?

While driving, you decide to change lanes from your current lane to the lane on your left.

Step 1: For the love of everything that is beautiful, make sure you actually have room to safely change lanes.

Step 2: Several seconds before changing lanes, pull down the turn signal stalk (usually located to the left of the steering wheel). This will activate the left turn signal by completing the circuit between the battery, thermal flasher, and turn signal light bulbs. It will let other drivers know that you intend to move your vehicle that direction.

Step 3: When the turn signal stalk is activated, the electrical current flows into the thermal flasher. At first, it flows into a resistor wire coiled around a short steel bar. The resistor heats up the steel bar, which causes the bar to expand.

Step 4: Attached to each end of the steel bar is a longer, curved steel bar. When the shorter bar expands, it straightens out the longer bar. The contact that connects to the turn signal light bulb is just hanging out until the longer steel bar touches it, which completes the circuit.

Step 5: As the longer steel bar is touching the contact, the resistor around the shorter steel bar cools down. That means the shorter steel bar cools down and contracts. That pulls the longer bar away from the contact, which breaks the circuit. That is, until the resistor is heated again.

The cycle of Steps 3-5 happens once or twice per second.

How Does It Stop Working?

Most vehicles have a self-canceling signal. Under the steering wheel, there is a notched hub. When the turn signal stalk is activated, it pushes a spring-loaded nub in between the notches of the hub. As the steering wheel turns the direction of the signal, the hub’s notches move across the nub. When you turn the wheel the opposite direction, the hub’s notches push the nub out, which moves the turn signal stalk back to its neutral position.

Breakin’ the Law

Ladies and gentlemen of Texas, I have confirmed that Texas Transportation Code requires that you use your turn signals. Ladies and gentlemen of other states, I haven’t confirmed the requirements for turn signal use where you live, but even if it isn’t strictly required by law, it’s certainly the safe thing to do.

Wait. Ladies and gentlemen of Texas, you say you don’t believe me? Well, CHECK THIS:

Sec. 545.104.  SIGNALING TURNS;  USE OF TURN SIGNALS.  (a)  An operator shall use the signal authorized by Section 545.106 to indicate an intention to turn, change lanes, or start from a parked position.

(b)  An operator intending to turn a vehicle right or left shall signal continuously for not less than the last 100 feet of movement of the vehicle before the turn.

(c)  An operator may not light the signals on only one side of the vehicle on a parked or disabled vehicle or use the signals as a courtesy or “do pass” signal to the operator of another vehicle approaching from the rear.

 Acts 1995, 74th Leg., ch. 165, Sec. 1, eff. Sept. 1, 1995.

Boom. *mic drop*

So, there you have it. Now you know what the heck a turn signal is, what the heck it is NOT, and learned about one of my biggest pet peeves. Just use the signal. Please.


Tell me what other automotive parts baffle you. I’ll tell you what the heck they are!

Written by Ben Scharff

Leave a Reply

Your email address will not be published. Required fields are marked *