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Q: I am not getting power to the tow/tail relay.

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i am not getting power to my tow/tail relay. i know the relay is good i energized and ohmed it out. i even bought a new one to make sure. i also know my output side is good because i put power to it and got light. I tested with my meter on the input side of the fuse box and i am getting no voltage when my running lights are turned on. My question is is there another relay i am missing?

You did not list the vehicle information you are looking at so I will be general in my answer. The vehicle will use a relay in most newer trucks to run the trailer lighting and other functions. You may have all the regular vehicle lights functions normal and then the trailer will not since the circuits are separate. You will need to check to see if the trailer has separate fuses and relays in a different location from the normal lighting. For instant a Ford Truck will have a separate accessory fuse relay box for trailer lights in the engine compartment and regular light circuits inside in the smart junction box. You will need to trace the circuit and see if it is just a blown fuse or a problem in the main fuse box circuits.

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