2009 Chevy Silverado 2500HD

Question:

I just hooked up my 12 volt accessory wire under the hood for power the 7-way trailer adapter. I also installed the required 40 amp fuse in the electrical box under the hood. I am trying to run a small pump 4 amps by plugging into the 7 way trailer adapter for a pressure washer to power that pump. I am getting 12 volts when I test the circuit at the 7-way connector, but if fails to run the pump. When I hook up to a trailer with a 7-way connector, the inside trailer lights power on as normal. My question, is my Chevy smart enough to knowinch when a trailer is hooked up and activate that circuit through a relay? When I do hook up to a 7-way trailer connector, my dash does say trailer connected. Thanks!

asked by: Greg T

Expert Reply:

Your Silverado 2500HD 7-way connector is properly delivering power to your trailer lights when connected, so we know there is not an issue with the connector. (The Silverado does not switch the 12V accessory power to the 7-way on and off; it is on at all times.)

I suggest you test your 12V pump for proper operation by connecting it directly to the Silverado battery terminals. If it functions correctly when connected in this manner, then the issue may be that the wiring in the tow package simply cannot handle the demand from the motor in the pump. The 12V power circuit from your battery is normally used to power a trailer breakaway kit or trailer lights. It is not really intended to power devices such as pumps.

You may instead want to install a set of remote battery terminals. These allow you to have 12V power (taken directly from the tow vehicle battery) in a remote location on the vehicle. You will need to use heavy-gauge wire for this installation, roughly 6- or 8-gauge, or as directed by the manufacturer.

expert reply by: Adam R