enblethen wrote:
It could be the flashers that are being installed. Normal flashers cannot handle that big of load.
Your profile does not show year of your Sierra. It would be good to know that to research whether yours have an available heavy duty flasher.
Do you have trailer package? You could look under the hood for those fuses. The trucks wiring works relays under the hood fuses and relay panel. These only work if the truck has towing package and the trailer is connected to those wires rather then being tapped off truck's lighting wiring.
You will get a lot of input about switching to LED lamps.
x2 Don't know much about Chevys but on Dodge and Ford that is usual. they all plug in, or did, just alike. The larger unit for RV or truck is physically larger. On a Dodge I had I had to use a dro pof silicone to hold it in. It was larger than stock Dodge Truck, to aid boat trailer.
