Blowing fuses...

[GL1500]

1997 C1500 5.7 Silverado. Yesterday I lost running lights, chime, dash lights etc. Got home from work and found fuse #14 (Cluster, Comfort Controls, Instrument Switches, Radio Illumination, Chime Module) had no power on either side.

Checked further and found fuse #9 had blown (License/Parking lamps, taillamps, door switch illum., headlamp switch illum etc.).

I replaced fuse #9 and all was good last night. It's been really wet/rainy here so I figured I might have some moisture in the trailer hitch wiring harness. This morning while driving the fuse blew again so I removed and unplugged the taillights, trailer wiring harness and it's still blowing the fuse. Checked under the dash and no obvious problems. The only added wires are for the brake control and tranny temp gauge and those appear to be done well.

I removed fuse #14 and and fuse #9 still blows. I think I'm still looking at exterior lights but not sure how this system works and I don't have a wiring diagram. Does Fuse #9 feed power to the headlight switch, which feeds power to the lights via fuse #14? I don't think it's related to the problem since the #9 fuse still blows after #14 is removed. Just trying to understand.

So I'm still guessing it's wiring/socket related but also wondering about the headlight switch. Is there a way to test it other than replacing it?

Thanks in advance for any advice,
Steve

 

[Justin S]

short to ground somewhere, good luck!

 

[Bob L]

Did you unplug the bed light connector or just behind the tailight? I would try unplugging the bed harness completely as that is easy. The last time I had light fuse issues it was my trailer harness.

 

[df2x4]

X2, check the trailer wiring harness for sure. They are a common issue.

 

[GL1500]

Update: After I posted the questions I removed the front parking lights. I found that in 3 of the 4 bulbs the glass had come loose from the metal bases. Evidently one of them was loose enough that they were shorting out internally. Replaced the bulbs and all is good.

Still looking for an answer to my question though to make sure I understand it correctly. Does Fuse #9 feed power to the headlight switch, which feeds power to the lights via fuse #14? Does anyone have a wiring diagram they could post?

Steve

 

[AK49BWL]

I know this is sort of an old post but what I'm looking at here, Fuse 9 does power the headlight switch and Fuse 14 AFTER the headlight switch, which then goes to the interior illumination bulbs.

http://www.ak49bwl.com/other/GMT400/Lighting-Exterior.pdf
http://www.ak49bwl.com/other/GMT400/Lighting-Illumination1.pdf

 

[GL1500]

Exactly what I was looking for, thanks!