Running Lamp Issue

M

Molly

i can't seem to find
Feb 7, 2014
65
0
6
DE
So i'm stumped kinda. Been messing around trying to figure out where the fault is that's causing my left side running lights to work (any running light feature, the 194, the 3157, and the left side license plate light) Also, idk if it helps but the 194 and the 3157 blink at the same time on the left side, rather than blinking sequentially like they should.

Anyway, I tested every wire in the harness to the tail light, everything works fine
I thought I had power going to the junction box, so I replaced it today.. Turns out I don't have power to the junction box. I keep loosing the wire because there are two looms back there and I don't see how they hook up. In the middle of the truck there is some kind of little can looking thing that I thought went straight to the junction box but it doesn't. However I do have power to that brown wire.

I'm hopping someone has a schematic or something so I can see where that wire goes. It looks like it goes up in the frame and the other loom runs down the side of the frame. I know the brake wire goes up in the cab and connects under the dash, so I'm curious if the running lights do the same..

Forgot, I checked all the fuses and everything is fine there..
Thanks.
 
M

Molly

i can't seem to find
Feb 7, 2014
65
0
6
DE
Tried everything I could think of. Ended up taking it to a shop where they told me it was the BCM? seems like kinda a lot for just running lights...


Quoted me 545.00 to fix. Seems like a stupid amount of money just to fix some lights..
 
M

Molly

i can't seem to find
Feb 7, 2014
65
0
6
DE
Tothemax said:
You replaced the junction box under the truck on the last cross member?
Click to expand...

Yea, didn't change anything. I didn't have power on the brown wire going to the junction box, but there was another brown wire on the last crossmember that did have power..

I think I'm going to just run a wire from the drivers side to the passenger side.

Im putting a roll pan on next weekend and that only has one tag light anyway.
 
chevyburnout1

chevyburnout1

Fixing it till it breaks
Aug 25, 2008
2,368
1
38
Berthoud, CO
The BCM controls the running lights but only the running light relay located in the underhood fuse block. From that relay it splits into three circuits: Front running lights, Right Rear running lights, and Left Rear running lights. The right circuit is a brown and white wire where as the left circuit is a brown wire. Both circuits run to the rear light junction block at the rear crossmember. Are you getting power at the 'LR PARK' fuse in the underhood fuse block?
 
M

Molly

i can't seem to find
Feb 7, 2014
65
0
6
DE
chevyburnout1 said:
The BCM controls the running lights but only the running light relay located in the underhood fuse block. From that relay it splits into three circuits: Front running lights, Right Rear running lights, and Left Rear running lights. The right circuit is a brown and white wire where as the left circuit is a brown wire. Both circuits run to the rear light junction block at the rear crossmember. Are you getting power at the 'LR PARK' fuse in the underhood fuse block?
Click to expand...

it's raining right now so i can't go out and check anything, but i had power to LR PARK in the engine fuse box. I had no power to the brown wire in the wiring harness after the junction box, I had no power to the brown wire right after the junction box, from there the loom goes in the frame and I'm not sure where it goes after that.

Now the part that confuses me is there is a loom that goes half way across the last crossmember. It has a brown wire in it and it has power. I thought that loom went to the junction box, which is why I replaced the junction box. When I replaced it and nothing changed, I looked again and noticed that the loom I first tested with a brown wire runs over the junction box then heads up to the front of the truck by where the e brake is.
 
Tothemax

Tothemax

xgmtech
Oct 16, 2014
607
8
18
new york
Those connectors at that junction block can get corroded. I would take that connector off and look at it good also give a light tug on the brown with white wire it may be green at the crimp
 
M

Molly

i can't seem to find
Feb 7, 2014
65
0
6
DE
Tothemax said:
Those connectors at that junction block can get corroded. I would take that connector off and look at it good also give a light tug on the brown with white wire it may be green at the crimp
Click to expand...

When I took them off to replace the junction box they all looked brand new..
 
M

Molly

i can't seem to find
Feb 7, 2014
65
0
6
DE
I forget if I posted about it but I noticed now I can't turn off my head lights.. Like when I turn that knob down nothing happens anymore


Sent from limp mode cat eye.
 
M

Molly

i can't seem to find
Feb 7, 2014
65
0
6
DE
Well I posted on another forum and was told that to disable the auto lights I had to press the interior light on/off switch a couple times and it would ding then I could turn the lights off. Well I pressed that button like a million times, no ding but now I can turn off the lights while driving.. So I guess that's unrelated.

And no, it didn't fix my running light issue, i had my fingers crossed lol.
 
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