Why would the right turn indicator stay lit whenever the headlights are on?

Answer 1

If BOTH turn signal indicators stay lit and don't blink when headlights are on, it could mean that the turn signal flasher relay that is sometimes located under the dashboard/and on the fuse panel is going bad. This faulty flasher/relay/fuse may continue to function and blink the turn signals when headlights are OFF, but the extra draw of power that the headlights require when they are ON could result in a a no-blink signal condition caused by a bad/faulty blinker relay that is on it's way out. Replace this blinker/relay/fuse after you check your bulbs. It is relatively inexpensive and should be replaced. I learned this on a full size 1989 GM pickup truck after spending money in the wrong directions first. It seems that I have had flasher relay problems with other GM cars or trucks that I have worked on.I would recomend you to check all of your turn, brake, and park lights if you haven't already done so. Sometimes a bad bulb will cause the problem you are having.

THE RIGHT TURN ,LIGHT ASSEMBLY HAS A BAD GROUND. SEEN IT HAPPEN LOTS OF TIMES.

If the problem started after a new turnsignal bulb was installed then pull the bulb and look into the socket. Make sure both the socket and bulb have the same number of contacts (both two or both one ). If a single contact bulb is plugged into a two contact socket it will short both of the contacts in the socket together and backfeed a power signal from either circuit into the circuit on the other contact.