right turn signal won't work when lights are on

I have the same problem except it's the left

you might try checking for a ground wire brokin or loose,or if you have installrd a wireing harnes for a tow behind trailer, try un hooking it see if any change, hope this helps whd-opn.

Hi did you check the wire harness for any bare wire or were the they connected to the front and rear.You have a power feed back from a broken wire or bad connection or a bad bulb socket. Good Luck.

did you use the correct bulbs in the sockets? Both the blinkers in the front and rear use a 2 phase bult with 2 filaments in them. If you use a single phase bulb on one side it will give you this symptom. Also when you apply the brakes the blinker indicator may come on in the dash (doesnt allways happen).

andrew and dedell both have good possiblities one more after you check those is some times when a dual elment bulb fails one element will drop and short to the other element inside the bulb and give you power feed back condion also inspect bulbs close

when I cut the lights on the signals not work or a brake light when I cut the lights on the brake lights work

We had the same problem with our 91 Chevy Silverado 4.3 litre v-6. The mechanic replaced the multipurpose switch and it worked great for a week then reverted back to the blinker not working consistently. We are going to look for a short in the towing wires.

Like indicated above, trailer light modules short out all the time and cause any number of lighting issues. When mine shorted out, anytime I turned on my right blinker all my lights would flash and my vehicle would drop out of cruise control, but everything was find using my left turn signal.

Have 1998 Silverado put blinker on and get four way flasher and dash lights flashing

I had the same problem and fixed it thanks to all of y’all’s answers. My right blinker would stay solid while my lights were on and my hazards and dash flashed when my lights were off. I ended up having a bad ground on my aftermarket 7 prong trailer light adapter. After fixing that, I developed hyper flash for both signals. I replaced my flasher relay found in the cab down by the parking break pedal and it fixed everything.

I had this problem one time before. And it was the plug under the back of my truck for towing.

I'm having the same problem but don't have a tow plug it's a 1992 and the driver side tail light won't work has new bulb but still nothing could use some help