Turn Signal relay location on a 2013 Petrbilt 386 (2024)

FAQs

Where is the turn signal switch relay located? ›

In most cars, the relay is in a junction box along with other relays. Some vehicle manufacturers label the relay on the fuse box cover to make it easier to identify.

Look into the wire harnesses and you will find a relay rectangular box labeled "electronic flasher". It is rust color and will also say "12 volt, 12 lamp". It is not mounted to anything, just laying there with 2 large 10 gauge white wires to it. The relay flasher pulls out and is 2 prong.

It should be behind the speedo and gauge cluster laying in with the harness. You will need to remove the gauge panel screws to flip the panel forward to gain access. It should be a rectangular flasher assembly with a couple wires going to it.

A car sends signals through the turn signal lights located at the four corners of your vehicle. These lights are activated by the turn signal switch located inside the car. This switch is activated by a lever that's installed right in the steering wheel or in a separate assembly near the steering column.

Starting relay position

The fuse box (also called the power box), the instrument panel under the fuse panel, or the right fender are all possible locations. In most cars, it will be under the hood, in a large box with a black lid. This is where car fuses and relays are installed. It is also called a fuse box.

The Turn Signal Flasher generates a timed on/off signal using a bimetal as we all know. The Turn Signal Relay is responsible for supplying high-current power to the appropriate lights, so the Multifunction Switch Stalk doesn't have to handle the ~15-20a of current drawn by all of the lights.

Additional lights aren't functioning — Along with your hazards, you could notice that other lights, such as headlights, daytime running lights, and even brake lights, aren't working. Other lights may be wired via or with the relay on some cars, causing a problem if the flasher relay fails.

Testing the flasher unit

Use a test lamp to check that power is reaching the flasher unit. With the ignition on, earth the tester and probe the feed wire connector:the lamp should light. To test the conventional type of flasher unit, use a circuit tester between the terminal marked B on the unit and the earth.

The fuse is in the PDC that's under the hood. The fuse will be labeled G1 - G8, probably G1 or G2 for headlamp. The CECU will communicate to the chassis node what lights to turn on and then the chassis node will send power to the light.

Where is the turn signal blinker? ›

On most cars, the turn signal lever is located to the left of the steering wheel. Shifting the lever up indicates a right turn and shifting it down indicates a left turn.

There is a starter interrupt relay behind the dash right behind the steering wheel. You can try to replace the relay or replace it with a bypass relay instead.

This may be in a power distribution block under the hood, or more likely a fuse block located somewhere in or behind the dashboard. Once the fuse is located, simply pull it out and push in a new one of the same type and amperage.

Common Reasons Your Turn Signals Might Stop Working

Burnt-out bulbs are the most frequent issue, but electrical problems like blown fuses, faulty wiring, and corroded connectors are also common. Additionally, a malfunctioning flasher relay can cause the signals to blink erratically or not at all.

If you're certain that your bulb is good but the turn signals still aren't working properly, there might be a problem with your vehicle's flasher relay, turn signal switch, or electrical system.

On average, it costs a total of $97 for a hazard/turn signal flasher replacement, which includes $43 for parts and $54 for the mechanic's labor. The exact replacement cost for you will depend on the type of vehicle you drive.

The process to replace your broken turn signal switch is pretty easy. Getting to the switch differs if you have an earlier column that doesn't have the key in the column or tilt options. If you have a tilt column and a key in the column it gets a little more complex but it's still not a bad job.