I messed up something while running a power wire for sub

cylon58 · February 25, 2019

2015 Silverado LT Crew Cab

BACKGROUND - Last night I ran a 0 gauge power wire through the big boot on the driver side dash. I first unhooked the battery. I used a sharpened coat hanger to poke through the book from the engine bay (stupid in hind sight). On my first attempt the coat hanger poked right through the big wiring harness that comes though that boot.

In the process I also unbolted the junction box behind the brake pedal and unsnapped the front connectors to be able to better access the firewall.

While I was running the power wire to the back of the truck I reconnected the battery to move the driver seat forward. While the battery was connected I accidentally touched the power wire to an unpainted bolt and grounded it very briefly on the truck.

behind the radio I installed a wiring harness from LLJ customs (pre built line converter harness).

PROBLEM - when I reconnected everything I have 2 problems. (1) The back up camera says "service rear vision camera" with a grey screen (no picture) (2) the gauge cluster display reads "Service power steering - drive carefully" and there is no power steering.

QUESTION - How screwed am I? would this be a fuse problem or have I most likely damaged an important wire in the wiring harness? Could the damage to a wire have caused more severe damage to an on-board computer? Can I diagnose and repair myself or should I take the truck to a dealership?

THE REAL PROBLEM - this is my fiance's truck, not mine - I need to get it fixed ASAP no matter the cost

1SLOW1500 · February 25, 2019

Can be many things as you say you did so. Many things. I would start with the easy stuff. Take a digital multimeter and check the main fuses. I would guess there isn't power on one of the main powers to the Connector. On the camera best to pull all history codes they will. Say low or no power blah blah. And then you can go right to that fuse wire. Or connector.

1SLOW1500 · February 25, 2019

Oh and next time buy the buy the largest zip ties and cut the head off drill 4 very small holes in the non pointed end I then safty wire through the cable. And electric tape it all up. I have pulled so hard as friend pushed I thought the grommet would pop out. But never damaged anything. Also check you connectors you unplugged. And reset everything.

cylon58 · February 25, 2019

42 minutes ago, 1SLOW1500 said:

Can be many things as you say you did so. Many things. I would start with the easy stuff. Take a digital multimeter and check the main fuses. I would guess there isn't power on one of the main powers to the Connector. On the camera best to pull all history codes they will. Say low or no power blah blah. And then you can go right to that fuse wire. Or connector.

Thanks for the reply. I can check the mains with a multimeter. Not sure what you mean about the camera... How do you pull history codes? will that somehow lead me to a particular fuse wire to check?

SS502 · February 25, 2019

1 hour ago, 1SLOW1500 said:

Oh and next time buy the buy the largest zip ties and cut the head off drill 4 very small holes in the non pointed end I then safty wire through the cable. And electric tape it all up. I have pulled so hard as friend pushed I thought the grommet would pop out. But never damaged anything. Also check you connectors you unplugged. And reset everything.

Simply the best way to get through that firewall period!

1SLOW1500 · February 25, 2019

Thanks for the reply. I can check the mains with a multimeter. Not sure what you mean about the camera... How do you pull history codes? will that somehow lead me to a particular fuse wire to check?

There are different levels of codes. We nickname them hard codes that turn dash light and soft codes. So soft codes say what sensors or divices are not working in the right range or voltage is wrong. It would then say camera voltage low or no current. The info for that says go to plug and check or meter then continue to where ever. Makes it easier on the dealers with these new fancy trucks.

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1SLOW1500 · February 25, 2019

Plate looks like this and the posts are numbered so it only goes back one way. I think you have to purchase the whole top piece. On the camera I would guess it is a damaged wire or disconnected. But if you pull up the diagram for the part you will know where the wire runs and if there is a connector. Go to gm part direct. Com and look it up. It take a like emagination but if your smart you can make sense of it.

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cylon58 · February 25, 2019

5 minutes ago, 1SLOW1500 said:

Plate looks like this and the posts are numbered so it only goes back one way. I think you have to purchase the whole top piece. On the camera I would guess it is a damaged wire or disconnected. But if you pull up the diagram for the part you will know where the wire runs and if there is a connector. Go to gm part direct. Com and look it up. It take a like emagination but if your smart you can make sense of it.

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I tested that piece because I was told that was the fuse for the power steering (the 175A). It tested OK. I am going to test all the other fuses under the hood for good measure, but beyond that I think I will have to take it to a professional. If the problem comes from where I pushed the coat hanger through the wiring harness I certainly don't have the time or ability to repair it. I could barely reach under there to pull the power cable through...

If It were easy to reach I would unwrap it and repair any damaged wires, but it seems impossible to access without some major disassembly...