Not really sure where to start with this, but my ranger recently developed an issue related to the turn signals (and climate controls).

Headlights off:

left signal turns on both left and right front signals, however the rear left works fine. Left signal also makes the climate control back lights flash.

Right turn signals work as they should

Headlights on:

left signal doesn’t work (stays on no flash) and climate control issue goes away

Right turn signal works as it should

something to mention:

there is a constant clicking of the turn signals even when the vehicle is off and key is out.

Help?

 

Welcome to the forum

1999 3.0l Ranger

There is a 4-way flasher button on the top of the steering column
Key off
Push it down and then go out and see if all 4 corners are flashing
If one bulb is not flashing its burned out, replace it

Turn and 4-way share one Flasher unit just under drivers side dash, could be failing, turn on a working turn signal and locate it by sound and feeling under the dash, it slide on to a tab, slide it and it will release and drop down enough to see it and change it for a new one

Google: 1999 Ford Ranger - Diagnose and Repair Turn Signal Failure
Watch the video

The turn signal stalk is called the Multi-function switch, because it does turn signals, wipers and washer and also high/low beam headlights

And because its a "moving mechanical part" it WILL wear out and can cause issues with any lights

Climate control lights are connected directly to dash/cluster back lights via the dimming wheel on the dash, so do the cluster lights also come on?
When climate light is on does Dimmer wheel control its brightness?