Expert Answers about Mercury Grand Marquis

• Troubleshooting Turn Signals Going Out When Brakes Are Pressed After 4-way Connector Is Installed
• Since the turn signals go out when applying the brakes in our 2009 Mercury Grand Marquis I recommend using a circuit tester like # PTW2993 on the green and yellow wires when you have the turn signal on and the brakes are being applied. If you are getting power on the green wire or yellow wire on your wiring but the turn signals are not working that means there is a grounding issue on the trailer side. I recommend double checking the main ground on the tongue of the trailer that it is...
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