Electrical/cluster short & 300 miles from home

[bretcopsey]

My brain is fried after an ordeal in TN to make a car purchase. Without going into the trials and tribulations of the day I’ll stick to the essentials for now.

We got stuck in a ditch due to sliding off the edge of iced pavement. The second guy that tried to pull me out lost momentum and traction and slid back into me busting up the front end of my truck. 95 C3500 DRW

We finally got out with the help of a third gentleman and by then it was dusk. Switched on the headlights and none of my cluster backlighting is working. Check engine lights up when cranking, bright indicator comes on but the cluster is otherwise dark.

Stopped and checked fuses, #9 was blown. Replaced, turned on switch immediately blew fuse. It’s now dark and we just went back to the hotel where we stayed last night instead of trying to make it home tonight. I have very basic tools with me and no easy way to really crawl around to check anything, but not seeing any pinched wires where I got smashed.

I don’t want to run the risk of burning down on the side of the interstate tomorrow either. Am I right to think that with the fuse blown, and headlight switch off (running in day time tomorrow) that I PROBABLY should be fine? Anything I can easily check/do in a hotel parking lot with basic tools to better my chances? I usually research this stuff first but it has been a 12 hour ordeal since getting stuck and my head can’t take it at the moment… thanks in advance for any advice I can get

 

[bretcopsey]

For what it’s worth, headlights, taillights turn signals all work. Didn’t notice anything acting differently etc. just dark cluster. I drove with headlights switched on for about 30 minutes before I got somewhere where I could try the fuses. So everything “seemed” fine.

 

[GoToGuy]

This happened after front impact? Or was anything noticed before?

 

[Road Trip]

My brain is fried after an ordeal in TN to make a car purchase. Without going into the trials and tribulations of the day I’ll stick to the essentials for now.

We got stuck in a ditch due to sliding off the edge of iced pavement. The second guy that tried to pull me out lost momentum and traction and slid back into me busting up the front end of my truck. 95 C3500 DRW

We finally got out with the help of a third gentleman and by then it was dusk. Switched on the headlights and none of my cluster backlighting is working. Check engine lights up when cranking, bright indicator comes on but the cluster is otherwise dark.

Stopped and checked fuses, #9 was blown. Replaced, turned on switch immediately blew fuse. It’s now dark and we just went back to the hotel where we stayed last night instead of trying to make it home tonight. I have very basic tools with me and no easy way to really crawl around to check anything, but not seeing any pinched wires where I got smashed.

I don’t want to run the risk of burning down on the side of the interstate tomorrow either. Am I right to think that with the fuse blown, and headlight switch off (running in day time tomorrow) that I PROBABLY should be fine? Anything I can easily check/do in a hotel parking lot with basic tools to better my chances? I usually research this stuff first but it has been a 12 hour ordeal since getting stuck and my head can’t take it at the moment… thanks in advance for any advice I can get

Greetings bretcopsey,

Sorry to hear about the accident, but happy that nobody got hurt in the incident.

Based on your problem description, I pulled up the '95 CK_Truck_Emissions_and_Wiring_Diagrams
FSM, and on p. 928 I pulled up the Fuse Block electrical diagram:

You must be registered for see images attach

Good news, in that the diagram does show Fuse #9 is for the parking lamps AND also
the instrument cluster backlighting. (Makes sense, for when I turn on the parking lights
I always verify if they came on by looking to see if the instrument cluster also illuminates.)

Of course the diagram shows that Fuse 9 is first sent to the 'Headlamp and Panel Dimmer Switch',
so I am going to have to dig a little deeper to find the wires going to the (smashed?) parking
light on the front of your truck, which I will do after I post this.

Big picture, driving with the parking lights off should not be a problem. And the problem shouldn't
spread to the separate headlight circuit, especially since Fuse 9 is blowing/not allowing excess
current through the aforementioned headlamp switch. (Thinking collateral damage to the switch.)

Proof that we have control over the situation would entail locating the wiring harness to the smashed
front parking light assy and seeing if you can find/clear the electrical short to the body/chassis.

I'm off to (try to) locate the relevant color codes in the parking light wiring harness so that you
will know what to look for in the daylight tomorrow.

Hope this helps. More in a bit.

 

[Road Trip]

OK, I found the big picture for the electrical circuit for the parking lights,
from Fuse #9 at the top lefthand corner of the page, through the Headlight switch, and
then to the Brown wires feeding the front lamps at the bottom of the page:

You must be registered for see images attach

Alright, referencing the diagram above:

* The bulbs on the LH (driver's side) should have the following wires to the bulb sockets:
Light Blue (flashing turn) Brown (parking light) and Black. (Ground)

* The bulbs on the RH (passenger side) should have the following wires to the bulb sockets:
Dark Blue (flashing turn) Brown (parking light) and Black. (Ground)

****

Given the above, if you were to find a brown wire with chafed insulation exposing copper wiring
to the body in the vicinity of the collision damage you have located the root cause of Fuse #9 blowing.
If it can't be disentangled, you could cut the brown wire before the collision damage, allowing
Fuse 9 to be replaced and not blow, proving to yourself that you have regained control over
this electrical issue.

Best of luck locating the damaged electrical wiring.

Safe travels!

 

[Road Trip]

No doubt this isn't news to you, but just in case the FSM shows it's (normally)
pretty straightforward to gaining access to the parking light connectors/wiring
harness:

You must be registered for see images attach

Let us know what you discover. And also if there's any other questions or issues that we can answer
in order to help you return to home base safe & sound.

To summarize, given the otherwise normal behavior of the truck (plus the fact that all the other fuses
are *not* blowing) you should be alright driving back home. Also, there is a possibility that the
turn signal wire that share the same routing as the damaged parking light wire are also damaged, so I
wouldn't employ them for the remainder of this trip.

Best of luck with the trip home --

 

[Sean Buick 76]

I would grab a new wire, in line fuse and Hotwire the headlights to get home.

 

[Road Trip]

For what it’s worth, headlights, taillights turn signals all work. Didn’t notice anything acting differently etc. just dark cluster. I drove with headlights switched on for about 30 minutes before I got somewhere where I could try the fuses. So everything “seemed” fine.

I would grab a new wire, in line fuse and Hotwire the headlights to get home.

According to the OP the headlights are still functional. My responses were more to show him
where to specifically look for wiring harness damage post incident that would also explain
the missing instrument cluster lights, and even so he should be safe to travel home in this condition.

And if he was able to find/clear the fault then even less worries on the way home today.
Few things make a road trip seem even longer than when your ride has suffered unknown
damage and all you can think of is, will the failure lead to the truck burning down on the side
of the road if I keep driving it? :-(

Or by the same token, if the turn signals proceeded to fail that this would actually make sense
given the shared harness routing, and not to worry that *everything* was going to fail. Back
in the day, we'd write up his truck as 'Code 2' (partially mission capable) and allow further use
until such time as we could have it for corrective maintenance. :0)

Seriously, if I were the OP I would simply avoid using the turn signals for the remainder of the trip,
and otherwise bring the machine home gently.

Here's wishing him an uneventful day today. (!)

 

[Road Trip]

I have very basic tools with me and no easy way to really crawl around to check anything, but not seeing any pinched wires where I got smashed.

I just reread your initial statement, and if you aren't seeing any pinched wires then possibly
it's something as simple as a damaged bulb socket? (Since the parking lamp and ground wires
are in close proximity to each other at the socket?)

Fingers crossed on your behalf. And the photo of the skating rink you were on -- wow.

Safe travels!

 

[bretcopsey]

I appreciate all the replies guys!

This is a brand new issue since the front impact. I’ve no electrical gremlins of any sort before.

So, update-Based on Road Trips excellent research and summary I pulled the driver side park lamp and inspected what I could access. There is nothing in the vicinity showing damage. The real kicker here is that all lamps including turn indicators are working. Something I had failed to mention is that I had performed the 4 hi mod and headlight relay mod a couple years ago.

All this said, it is currently single digit temps out so unless anyone replies back urging me not to, I think we’ll get on the road and not use lights and turn signals.

To recap
all exterior lights work with blown fuse/fuse removed

Turning off lights, replacing the fuse with lights still off-nothing noticed with anything functioning abnormally

After fuse had been replaced, turn light switch to first setting for park only, fuse blows (audible without engine running) park lamps on

And continue to headlight setting, headlights come on

Since switching on the lights is when the fuse blows, I’ll just leave them off. And not use turn signals….

Damage is on hood, grille and bumper trim