Jollyradar

2000 Tundra
Ok so I have no turn signals or hazard lights (front or rear), but parking lights work.

Turn signal switch tests good.

Replaced flasher module with a new from Dealership.

I have power into the module, but no power out of the module. Ground tests good at the module and switches.

If I jump 12 volts to the left or right wires at the flasher relay, the 5a turn signal fuse blows.

I've got the wiring diagram for this system, but I can figure out why the flasher module isn't sending power.

Thanks for the help

RAD4Runner

Typically you would have separate fuse/power sources:

• Flasher
• Tail lights and
• Hazard and horn

The turn signal switch takes power from turn signal circuit which is only on when ignition is on.

The hazard signal and horn takes power from circuit/fuse that is on regardless of whether ignition is on or not. Find these two separate circuits.

Look at where the turn signal switch takes power from.

Look at where hazard switch takes signal from. Check that circuit for broken connection or blown fuses.
For a thorough inspection of a fuse, you need:

1. Visual inspection, AND
2. Voltage measurement on both sides of it, with negative probe referenced to ground, and load applied.

Jollyradar

All of the fuses are good. Voltage is good to the switches and the flasher module.

Does anyone know how the flasher module works? Is there a schematic for how it works internally anywhere? It is not a standard relay so it is impossible to know what it is doing just by observing it.

RAD4Runner

Here's how relay works for hazards or for turn signal. Please refer to your truck's actual schematic for wire colors and pin-outs.



So...
You are getting a voltage if you measure between pin 2(ground) and "power" pin?
Yet no clicking?
If so, then, it's a bad relay.

I have a 22RE-liable but could surely help others with other engines. However, what's "the left or right wires"?
Wanna post your schematic so we can "see" what's going on and help?

Jollyradar

Yes that is how a relay works.

The Tundra does not use a standard relay it uses what they call a flasher module. From memory, it has 8 pins.

Ground
Left turn circuit
Right turn circuit
left turn switch
right turn switch
horn
+12v
wire to integrated control

So the flasher module has power to it. The ground is good. The switch circuits are good (+12v).

I would agree that the module is bad, except that this is the 3rd module I've tried, and its new.