Odd Turn Signal Behavior

[jschildm]

I pulled the bed to do the quick fill mod. As we were lifting it up, I noticed I forgot to unhook a plug, it got pretty tight, but didnt see any damage. We only picked it up a couple feet, and there was another harness that looked like it T'ed and went to the trailer wiring harnesses (one at bumper, one in bed).

I got everything put back together and now the turn signals are acting weird. All of them work, but when you originally turn them on, they take a while to begin blinking, and the blinking isn't the same it used to be. It behaves the same way if use the flashers instead.

I doubt it is a bulb or flasher since both the turn flasher and blinker flasher worked fine before, and both act the same now.

My initial thought would be a messed up ground or something, but don't have a good plan for finding the problem. Any help with troubleshooting would be much appreciated.

Thanks.

 

[POWER-STRUCK]

do you have a ohm meter?

 

[jschildm]

I do indeed.

 

[POWER-STRUCK]

are you ready to do tests now or do you just want a wiring diagram?

 

[99 ol'red]

Check your trailer pig tail where you hook up the trailer lights and make sure no wires are touching, if they are seperate them, happened to me several times, thought I had a big issue but took seconds and no money to fix

 

[Bugman]

Check the grounds.

 

[jschildm]

are you ready to do tests now or do you just want a wiring diagram?

It won't be today, but I should be able to work a few evenings at it this week. I wiring diagram would definately help as well.

Check your trailer pig tail where you hook up the trailer lights and make sure no wires are touching, if they are seperate them, happened to me several times, thought I had a big issue but took seconds and no money to fix

I am wondering the same thing, as that got pulled on a bit also. I am just worried its not right by the plug, and could be further up in the harness, which won't be very easy to get too. I will can definately start looking there though

 

[jschildm]

Any specific grounds to start with?

 

[jschildm]

I think my plan right now is going to be to check the trailer plugs (bumper and in-bed) with an ohm meter and see if any are touching that way. Also check the ground to ensure its still connected. Depending what I find there I might unhook the T plugs where the lights are connected to the truck wiring and see if it still does it. By my logic, this would narrow it down to the trailer harnesses.

Thoughts on whether I am on the right track or not? Better ideas?

 

[jschildm]

OK, so I messed around with it briefly today and found a few things. The first thing I discovered was that my battery had gotten ran dead. It has been a few weeks since I started it, but it wouldn't do that in the past. The next thing I did was unhook the wiring harness for the trailer wiring and it seemed to make no difference. I hooked it back up, and tested all of the prongs. They were all open circuits (relative to ground) as they should have been, except the left and right turns. My crappy Digital Volt Meter was saying -.06 or something like that. Also, when testing the left turns/brakes relative to the right turns/brakes weren't an open circuit, but I am not sure if that is normal or not.

On a side note, a guy that was helping me said he noticed smoke after I had ground the bolt off and was knocking it through the frame. This would be the bolt right where harness runs under the rear tank along the frame rail (middle bolt, drivers side). I have inspected the loom as best I could and didn't really see anything obviously destroyed, but have a feeling it could very well be the source of my issues.

Does anyone have a wiring diagram for the wiring along the frame and rear bumper? That would help me see what I needed to start testing.

 

[jschildm]

Does anyone have a wiring diagram for the wiring harness running to the rear of the truck along the driver's side frame rail?

 

[jschildm]

Ok, I found a site that had a lot of wiring information for me, so that should be handy for investigation.

i am a little confused now though. We got some snow here in Iowa last night and this morning so I drove the truck to work this morning. Last night I unhooked the trailer wiring harness and got it ready to go. Driving it today with the truck running, I could tell no difference when using the turn signal from before. I dont know if its just less noticable with the truck running, or if it has had the problem for a while, and i never knew it before. I still think there is something wrong, since the Left and Right turn dont act as they should when testing continuity to ground. At least I know it runs, drives, and isn't unsafe (slow/no turn signals).

 

[Russ]

IIRC there are two flashers for the turns and hazards. I'd try swapping, just to see if it makes a difference

 

[jschildm]

I might still try doing that since its easy enough to do, but when I first started the investigation, both the turn signals and the flashers acted in the same manor.

 

[jschildm]

So I have slowly been checking a few things related to the turn signals as I continue to drive the truck, which acts "normally". At this point I am convinced it is acting just like it did before the project, but I still think something fishy is going on.

I have been trying to move forward in the system and check it to see where the "closed circuit" is. Looking at the wiring diagram I have moved from the trailer tow fuses, to the flasher, to the turn signal fuse in the cab. The fuse as as far as the wiring diagram goes, and when I check it with the fuse out, one space is open, and the other is a closed circuit.

I am curious what wiring there is to the fuse panel for the turn signals to try and trace the root of the issue. Maybe I am chasing a figment of my imagination, but I don't believe it should be acting like it is with the DVM.

 

[jschildm]

I was curious if someone could do me a favor. I just want to make sure that I am not chasing a figment of my imagination.

Could someone check continuity for me in their trailer plug on their truck between the ground prong, and both the left and right stop/turns and let me know what theirs says?

 

[jschildm]

Anyone get a chance to check if the this for me? I think I am going to take my DVM with me to work tomorrow and check another OBS Powerstroke someone drives to see what its like. Hopefully I dont look too suspicious. haha.

 

[Bugman]

The trailer plug wiring should have nothing to do with the trucks turn signals since it is on a circuit of it's own and separate fuses.

 

[jschildm]

It does if the problem is forward of where the two split off, which I believe mine is. I get the same readings whether I am checking from the trailer turn fuses, or the truck turn fuses, and from the flasher module, for that matter. The trailer plug just happens to be the easiest place to get to and check.