Trailer wiring issue. 2000 expy

[GaExpedition]

Been having on and off issues with the right turn/parking light circuit on my 2000 expy. First, it was intermittently blowing the fuse under the hood. Now it's to the point of not working at all even after replacing the fuse. I have also checked the fuses inside the cab and all are fine. After doing a few searches here, I read that there should be 2 wiring harness connections under the truck. I know one is at the back where the 7 way plug connects, but I can't find the other so I can track down where the short may be with my multimeter. Anyone know where it's located? If not, will it hurt if I bypass that particular wire, and just run one from the right rear turn signal itself to the 7 way plug?

 

[stamp11127]

Try looking around the coolant surge tank, that is where the other one is on the 99's.

Running another wire is last resort - kind of quick and dirty. Plus you don't know where the short is. When you blow fuses the problem will be between the fuse and the ground point of that circuit.

Just for giggles check the bulb on your right side. I've had bulbs blow fuses by dropping the resistance down enough that the fuse would blow. As resistance drops current flow increases.

Now, bulbs are the first thing that is checked when troubleshooting light circuits.

 

[GaExpedition]

Thanks for the tip. Found the connection right under the air filter housing, behind the over flow bottle. Once the air filter housing was out of the way it was easy to figure out. Had good ohm reading from there to trailer plug, so I checked for voltage before and after the plug under the hood and sure enough that's where the problem was. No matter how much I tried, I just couldn't get voltage to pass through the plug so I just cut the wire on both sides, and added in a jumper with male to female insulated stacons. Works like a charm now. Now I can be a little less stressed on those early morning drives pulling the boat to go fishing.