Courtesy Fuse keep blowing

[454ssdude]

So, I have a suspecion this is self inflected but my Courtesy Fuse keeps blowing. The back story is that I thought it would be nice to run the USB input and I added a USB grommet so that when I close the ashtrey, everything was hidden. I removed the old cig lighter and left it up plugged. Could this be causing the issue and if so, what can I do to solve it without adding the Cig Light back?

 

[Vanishing Point]

First we need to know some important information before we can attempt to give you some guidance regarding your concern, such as the Year, Make, & Model of your particular vehicle in order to give a somewhat correct diagnosis.
But just by what you wrote it seems to be self inflicted. What was it doing before all this? And yes this could be causing you the extra frustration, and that it might have been better to leave well enough alone. There's and old saying "if ain't broke, don't mess with it!" Let's see if one of my colleagues chimes in with an answer to your problem once they have all the correct info from you first. Sorry for not being able to help you more better with your dilemma, but I'm sure someone will. Good luck!

 

[454ssdude]

My bad... Completely forgot to include that. It's a 1990 C1500 regular cab. I bought the truck and started restoring it. I'm not sure what it was doing prior to because I just completed the interior and starting wiring the aftermarket radio. I realized the issue because I wasn't getting 12v constant pwr on the radio (yellow) but was on the 12v Ignition (red). The ground was good too. I've double checked my wiring the radio and that shouldn't be the issue. I checked the fuse, and saw it was blown. Changed it, it it blew immediately.

 

[GoToGuy]

I would refer you to the 90 factory service manual. Lookup what items are powered by courtesy fuse. If you have the 90 owners handbook, glove box thing nobody bothers to read, it lists all the fuses and what items get power from which fuse. They can be downloaded for free online various and GM heritage site. Begin with those.
Was it blown before you acquired the truck? Did your mods create this problem? If was blown before mods began , certain items would not functioning, a cause for concern.
Did you use a USB adapter built for splicing into 12 volt power input, with drop-down to 5 volts? Are you SURE your USB is wired correctly,with no shorting during movements?
If you don't have factory service manual with wire diagrams , download here, forum , free. It's your electric best friend.
That's the path I would take. Yeah it sounds redundant, but it's not a water leak " oh hey that fittings loose".
Good luck.

 

[454ssdude]

I found the issue by troubleshooting everything on that circuit... now I need to figure out how to fix it. The issue is with the Dome light assembly. Once I disconnect the dome light, the fuse works, the radio turns on... everything is fine. The moment I pop the dome light back in the fuse blows. What do you guys think? Bad ground? The dome light has two parts that plugs together. Then there's a screw that grounds it out. The fuse will blow before I get the ground screw in and at the moment I connect the two parts together.

 

[454ssdude]

Could it be the door jam switches? I replaced the driver's side but the passengers side is the original

 

[454ssdude]

Welp... I'm the idiot... I figured out what was happening. I used a screw to hold the dome light trim in place and that screw was coming in contact with the dome light assembly and shorting it out. I removed the screw and bam! all fixed. Thanks for the help everyone.