AUX Switch Issues

[Captain CABO]

I've been trying to diagnose an issue I'm having with my AUX 1 switch. I've had my AUX 1 running a Baja Designs 37" OnX bar for the past year with no issues at all. Last Saturday during a pretty rough run through some washout sections of Havasu desert I noticed my lightbar was off. Sure enough, fuse 18 (30 amp) was blown. I put a new fuse in, everything worked fine and I went on my way.

Fast forward to two days ago. I go to flip on my bar to blind a Prius that wasn't moving at a light (far more effective than the horn) and nothing worked. Went under the hood and the same fuse was blown again. This time when I went to go put a new fuse in it pops instantly. Here's where I'm having issues. I disconnected the light bar and disconnected both the connections under the dash (yellow to red wire) and under the hood but I'm still getting power to the fuse slot. With nothing on in the truck, key in my pocket, I am getting power to the fuse slot where Aux 1 should be.

I know this means I have something hot in the truck but I just can't figure out where it could be coming from. All the connections I have made are sauntered and heat shrunk over and I've been over every inch of wire and through every light connector I have put in. The wires to and from the fuse box in front of the motor are all bundled in the factory loom so I can't see where there would be an issue in there. All my other AUX switches are working just fine, it's only AUX 1 that's being a bitch.

Any help with this would be appreciated. I called Ford but it was a waste of 10 minutes.

Any ideas?

Barrett

 

[Rookie]

With a fuse blowing, the first thing I'd check is for a short. Do you have a meter?

 

[Captain CABO]

I've had a meter on it. I know I have a short I'm just trying to figure out where it could be. I have a feeling something happened over the weekend and I may rubbed through the wire for AUX 1. I just don't understand why it has constant power.

 

[Rookie]

Idk about the constant power. I'd disconnect everything and start behind the dash, working your way toward the lights.

 

[The Car Stereo Company]

if you have a short, it might have melted the aux wire to a constant. i have seen melted wires before and its not a fun situation to deal with. hopefully that is not the case. but check to see if any wires are melted

 

[Captain CABO]

if you have a short, it might have melted the aux wire to a constant. i have seen melted wires before and its not a fun situation to deal with. hopefully that is not the case. but check to see if any wires are melted

From everything that is showing nothing is melted. I haven't opened up any of the factory wire looms to check though. I'm trying to see where any wire could have possibly rubbed but I just don't see it.

If I had just installed the bar it would be one thing but i've run it for a year with zero issues at all. As much as I would hate to take it to the dealership I might just go that route, I dont want to do start cutting into the factory wore looms unless I absolutely have to.

 

[LONGISLANDRAPTOR]

Check to see if all the other AUX fuses are hot when the key is off. That may be a normal operation and your chasing nothing there. if they are not and only that fuse is hot with key off, then you have a short to constant power on the feed side. Dose the fuse blow the second it is inserted or the second you flip the switch?

Next if the light is disconnected and you still blow the fuse its most likely a short to ground on the power wire feeding the light. The aux switches are relayed. There is a low and high current side.

The wires that you connect to the light under the dash are high current and is not directly wired to the switch.

The easiest way to find the short in my opinion is to disconnect the feed wire to the pass trough wire under the dash. if the fuse still pops you know its not in any wiring under the hood. If the fuse doesn't pop, now you know the short is not under the dash but either in a pass through wire, or in the wire you ran to the light.

Any questions i will be glad to help. I don't check here much but PM me and i will get it right away.