Posted 2018-04-14 8:31 PM (#171520) Subject: Electrical issue, what does this mean?
Regular
Posts: 76
Location: WI
I have a 7 way big round plug on my truck. When I insert test light, the 12v light and the brake light both light up. I gather there's an issue with brakes, but what are the possible issues I need to look at? Trailer shop said it was back feeding and they cut power to my brake box and light went off. I installed new brake box, no different so I don't think brake box is the issue. What else can I check? I'm very novice with lighting if you hadn't guessed.
Posted 2018-04-14 9:36 PM (#171521 - in reply to #171520) Subject: RE: Electrical issue, what does this mean?
Extreme Veteran
Posts: 448
Location: Los Angeles, Ca.
Not sure...the voltage you see on the test plug light might only be a small current used to tell if a trailer is connected. Try a real test light to the brake prong and ground and see if it lights up....test light draws more current than the led on your test plug. Operate the brake controller slide switch and see if the the test light changes when you move the slide. Does the controller operate the brakes? You can also plug in the trailer and listen ate the wheel hubs and you will hear noises coming from the brakes. There is a trailer plug wiring link on this site to find the proper prong to test
Posted 2018-04-15 4:03 PM (#171525 - in reply to #171520) Subject: RE: Electrical issue, what does this mean?
Regular
Posts: 76
Location: WI
No, dealer used a plug like in the link. I'm going off what they told me but I don't have much faith after I fixed brake controller and still having same issue. We are thinking the issue night actually be my light plug and it bring wired slightly incorrect.https://www.etrailer.com/Wiring/Tow-Ready/TR20117.html?feed=npn&gclid=Cj0KCQjw8MvWBRC8ARIsAOFSVBVqApDuaCzIKZZy2IsGtfC-SqCR_H53eKWMGgTB1u0V5_dEUZtd6NAaAuSrEALw_wcBhttps://www.etrailer.com/Wiring/Tow-Ready/TR20117.html?feed=npn&gclid=Cj0KCQjw8MvWBRC8ARIsAOFSVBVqApDuaCzIKZZy2IsGtfC-SqCR_H53eKWMGgTB1u0V5_dEUZtd6NAaAuSrEALw_wcB
Posted 2018-04-16 11:57 PM (#171528 - in reply to #171525) Subject: RE: Electrical issue, what does this mean?
Expert
Posts: 3853
Location: Vermont
If this is the device that had two lights on...then you want to take the truck plug apart because you have corrosion in the plug that is tying the 12 volt power circuit to the brake circuit.
Posted 2018-04-17 1:44 PM (#171529 - in reply to #171528) Subject: RE: Electrical issue, what does this mean?
Regular
Posts: 76
Location: WI
PaulChristenson - 2018-04-16 11:57 PM
If this is the device that had two lights on...then you want to take the truck plug apart because you have corrosion in the plug that is tying the 12 volt power circuit to the brake circuit.