Turn signals on Mitsubishi Outlander work properly on the outside but both arrows on the instrument cluster turn on. Both left and right arrows turn on regardless of which way you press the turn signal switch. You will also notice that the turn signal arrows on the dashboard flash but are not as bright as they should be.
The problem: One of the contacts for the turn signal bulbs inside the instrument clusters is loose and may need resoldering. You will need to open up the cluster and check for continuity from the turn signal LED bulbs to the electrical connector plug. In our case, we found an open circuit.
Follow this procedure to troubleshoot this problem.
Remove instrument cluster from the dashboard.
Open the instrument cluster. Remove the back cover from the instrument cluster.
Once the circuit board is exposed inspect the contact where the turn signal sockets are connected to the circuit board. In our case one of the turn signal socket pins was broken and not making contact with the circuit.
This is typically due to instrument cluster failure. In some cases, you may need to replace the cluster. It is possible to fix the existing instrument cluster if you know how to test electronic devices.