Blowing turn signal and brake light fuses

[coachbarnes]

Doing my last check before heading West and I don't have turn signals. I checked bulbs, they are OK. Checked turn signal fuse and it is blown. Replaced fuse, turn key on and lift turn signal lever - fuse blows. I'm replacing with smart fuses, so I can see right away when they blow. Just for grins, I check brakes. No brake lights.. Check fuse and it's blown. Replace fuse, hit brake pedal and fuse blows. All other lights (tail lights, side markers, headlights) work fine. Just blowing those two fuses. I picked my truck up today from a transmission rebuild. Any chance one of the mechanics smashed a wire or something? What's the best way to troubleshoot this? I've got a centech harness, btw.

 

[Viperwolf1]

Very good chance of a smashed wire right where the cross member meets the frame.

 

[Viperwolf1]

You can unplug the rear harness and see if it still blows fuses. The connector will be right behind the drivers side inner fender.

 

[coachbarnes]

You can unplug the rear harness and see if it still blows fuses. The connector will be right behind the drivers side inner fender.

Thanks much! I'll do that first thing in the morning!

 

[coachbarnes]

Well, it wasn't anything obvious. To compound the problem, the wiring was done during a frame off and we decided to run things inside the cab. Hindsight, maybe that wasn't a great idea. Anyway, in addition -- I'm not sure "when" the problem started happening. I got it back a few weeks ago from a new EFI install, and it's REAL possible that's when it started because I took it straight from there to the body shop for a new hood then straight to the transmission shop for a new converter. So I haven't had it in my possession for more than a day or so since the new EFI was installed. They were all over the wiring harness, so I'm betting a wire got dinked up during that process. I disconnected the front blinkers trying to isolate the problem, but they still blew so I can rule them out. I'll do the same to the rear assemblies, but I'm loaded up headed to Moab. Maybe when I'm there some electrical genius can help me troubleshoot it. I'm good running trails with no brake lights and turn signals...

 

[KBUCK1]

Well, it wasn't anything obvious. To compound the problem, the wiring was done during a frame off and we decided to run things inside the cab. Hindsight, maybe that wasn't a great idea. Anyway, in addition -- I'm not sure "when" the problem started happening. I got it back a few weeks ago from a new EFI install, and it's REAL possible that's when it started because I took it straight from there to the body shop for a new hood then straight to the transmission shop for a new converter. So I haven't had it in my possession for more than a day or so since the new EFI was installed. They were all over the wiring harness, so I'm betting a wire got dinked up during that process. I disconnected the front blinkers trying to isolate the problem, but they still blew so I can rule them out. I'll do the same to the rear assemblies, but I'm loaded up headed to Moab. Maybe when I'm there some electrical genius can help me troubleshoot it. I'm good running trails with no brake lights and turn signals...

My new centech harness kept blowing those fuses and found out it was the wires at the brake switch on the pedal. The connected would barely touch the pedal housing assembly and blow the fuse.

 

[Viperwolf1]

I'm loaded up headed to Moab. Maybe when I'm there some electrical genius can help me troubleshoot it. I'm good running trails with no brake lights and turn signals...

Which campground you going to be in?

 

[coachbarnes]

Staying in a condo about 1.5 mi from Moab Rim campground (according to maps). Are you going to be there?

 

[Viperwolf1]

Staying in a condo about 1.5 mi from Moab Rim campground (according to maps). Are you going to be there?

I did a drive by early last night but we'll be coming out with the Bronco on Tuesday.