Short to Ground on 98 K3500 HL circuit pls help!

[9812VDuslly]

My 98 K3500 blew the 20A fuse #9 in the ip for marker lamps when I hit a pothole the other night. Replaced it. "Pop" when I switch on the headlights.

Initially it was intermittent. And then it became everytime I flipped on the headlight switch it would pop.

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To try and isolate the problem and find my short to ground, I cut the ppl/WHT wire coming out of the headlamp switch and turn on headlamps (HL). Still popped.

Reconnect ppl/WHT and cut brown. Flip on HL. No pop. Ok so short is on exterior lamp circuit.

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[9812VDuslly]

I remembered awhile ago my turn signal (TL) fuse would pop when using my left turn signal. #let'sstartthere

The splice (S210) for the EL circuit is underneath the dash so F that.

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Let's disconnect the headlight harness connector at the driver side firewall. New fuse. HL on. No pop.
Bueno. Proceed.

Pull side marker lights, turn signal bulbs etc. Check for resistance between bulb sockets + & - and engine block. With a short to ground i know I'm just looking for something weird. A higher amount of resistance or open circuit on one of these that isn't on the others. I planned to just ohm out whatever circuit was weirder than others.
Well, sonufabish
Left side marker light blue wire gives me open circuit reading.

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[9812VDuslly]

I ohmed out the blue wire at the socket to the S119 splice. Good reading. I get resistance.
#thatsferkinweird
Retest bulb socket.
I get good reading this time. Huh?

I ohm out whole circuit. From bulb to female connector at firewall. From male connector at firewall to blue wire at cluster plug in which powers left turn signal on cluster. All are good, closed circuits.
What?

Almost forgot. Sometime in between all this I plugged bulbs in with new fuse and flipped HL switch on. No pop.
But left side marker light is unlit.
I unsheathed Whole HL harness of conduit. Checked all for break or missing wire cover etc.
Nothing.
It's getting dark and cold quick. Put it all back together. Start truck. Flip HL switch on.
Marker lights all work. Cluster lights do not turn on.
FOOOOOOKKKK!!!!
At this point I'm at a loss.

Thoughts, ideas or experiences?
I'm ready to take it to a dealership at this point. I've been messing with it for 2 days.

 

[Erik the Awful]

Intermittent problems are the devil, Bobby Bouchet. It sounds like you're doing good work of isolating it down, but you can only troubleshoot it when it's acting up, and only when everything else is working right.

Check all your fuses - I see more than one on those diagrams.

Take a deep breath and think of how much beer you can buy with the money you'll save by not taking it to a dealership where the technician likely has less experience than you. The average technician stays in the field less than four years. You'll either have an amateur dorking around in your wiring, or it'll be some old guy who isn't smart enough to figure out he's getting screwed daily.

Then remember that your truck doesn't hate you. It's sick and needs help.

 

[9812VDuslly]

Thanks Erik,
I appreciate the reply. All fuses are good. Dash lights finally started to work. Randomly.
But the dimmer on my gauge pod gauges does not. I gotta pull and check those next now. Then I'll go back through the HL harness and main harness and clean and reground everything.

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It think I'll get those Big 3 ground straps that that fella on here sells. I don't know what else to do besides that.

I'll post updates here as I make progress on it. Maybe it'll help someone else.

 

[JOHNGAAA1]

Try tilting the column, you could have a shorted harness in the multifunction switch in the column. Common problem.

 

[9812VDuslly]

Try tilting the column, you could have a shorted harness in the multifunction switch in the column. Common problem.

Reviving a dead thread here.
The HL problem just went away on its own. Stopped blowing fuses one day, and that was that.
Recently my #16 fuse has been blowing.

This is an internal problem in the plastic switch housing itself, ya? Cuz all the wires coming out the back of the connector on the multifucntion switch look good.

 

[9812VDuslly]

Alrighty, so after some reading, thinking and tinkering I believe I narrowed down the problem.

Initially, it appeared, whenever I would use my blinker my #16 fuse would pop. After paying closer attention it seems whenever I made a turn and the blinker trigger would catch, that's when my fuse seemed to blow.
I pulled my wheel and column case halves to look at the wiring coming off the back of the multifunction switch (msf).
When those checked out ok I started thinking it was an internal problem with my msf. When I removed it to look at it I noticed this:

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This is the back side of the trigger mechanism for the turn signals. It was open slightly more with the spring protruding a bit before I pushed it back in. It should look like this picture here:

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So seeing this I started looking around and found this clean spot here where it looks like it's been contacting:

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I don't see any arc marks and it is an aluminum surface so I should see more than just that clean surface but we'll see.
I pushed that copper tab back in and put some Gorilla Glue on it. (I really don't want to buy another $250 msf)

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I'll test it tmw and if it works ( it pops the turn signals out after pushing the trigger in) I'll put all back together and report back here if the issue blowing fuses resumes.

Hope this helps someone else.

 

[9812VDuslly]

Edit.
Not it. Still was blowing #16 turn lamp and b/u fuse.
Fixed it here :

Turning steering wheel blows turn signal fuse

98 K3500. Turn signal fuse started blowing awhile ago when engaged. Now it blows whenever the steering wheel is turned too far one way or the other. I just replaced the multifunction switch. Not it. Still doing it. I'm at my wits end with this ****** truck. Shoulda bought a Toyota. Anyone...

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