Hello to everyone,
I have a question in regard to my 2002 chevy s10 2 door 4.6 liter V6 2 wheel drive chevy blazer.
I am having an issue with blowing fuse #8 which is part of the courtesy lamps interior schematic. The fuse pops with all power off with the key out of the ignition. On two separate occasions in the past few days I put the fuse in and it did NOT blow while the vehicle is parked. When The lights were operational, I checked to see if all the bulbs on the interior bulbs were good and all lights were operational. The vanity light in the sun visor do not work and the bulb for the light under the hood is burned out as well. However, all other interior lights, including dome and the lights in the overhead compartment are operational when the fuse isn’t blowing. I do have an after market stereo and have checked the wiring schematic for that to insure that it is wired correctly. IN both occasions when the interior lights had been working, the fuse blown shortly after I would begin to drive the vehicle. Which leads me to believe that there is a short that is grounding out when I drive the vehicle. I DO have the schematic diagram for my vehicle so my next step is to trace each component and check for shorts. I am puzzled as to why the fuse will blow even with the key out of the ignition. Although it is my understanding that power is continuously supplied to fuse 8. My cigarette lighter is unplugged and had previously been removed. I am wondering if anyone has any suggestions or can simplify the pain staking task of tracing each component in the courtesy light schematic. ANY help, suggestions or advice is GREATLY APPRECIATED! THANKS in advance for your post!

 

You've got a not so fun problem here. Best advice I can give is to start unplugging things, one at a time, until the problem stops. You could do a batch of unplugging too, just remember what stuff you took out. Unfortunately, there's no easy way of checking for intermittent shorts
You said you have the wiring schematic for your vehicle, try figuring what all is attached to that fuse and start disconnecting. Definitely unplug those burnt out bulbs, they're not doing any good anyways. If you know that any work has been done to your electrical system lately, start there (i.e. stereo, cig. lighter, etc).
since your problem only happens when driving the vehicle, manually checking for shorts is not an easy option. I suppose if you have a friend that's willing, you could check each component with an ohmmeter (with the fuse out) while your friend bounces the truck up and down, but that's certainly not a guarantee of finding your issue.
Best of luck, be prepared to invest some time

 

THanks for the response. I was really surprised that the fuse still blows when everything is turned off and the key is removed from the ignition. IT is so odd how it worked a few times then quits ha frustrating to say the least. I may end up just taking it to a shop that specializes in electrical issues for vehicles. However, I am going to check what I can get to with ease after work today and hope I run across it by chance, LoL.

 

I have no idea what shop would cost you for a problem like this, but I don't think I would ever let anyone do electrical work on my truck. Just too easy to be careless and cause problems down the road (wrong crimps, improper connections, improper wire routing, the list goes on). But to each his own. I'm well versed with electrical things, so doing my own wiring is easy for me. I can understand how it can be not so easy for other people.

but anyways, as far as the fuse blowing without the key in, that sounds normal. There's a couple fuses that always have power applied to them, the radio/interior lights among them. That's why your interior lights turn on before you turn on the truck (makes sense right? ). One other thing that occurred to me, is it possible that your electrical system requires more current than that fuse will allow? You didn't say the rating of the fuse you're replacing. If this problem occurred out of the blue with no new electrical devices installed (radio), then upping the fuse rating is a bad idea as the problem lies elsewhere.

Rest easy knowing that problems like this are usually something really simple to fix, just takes awhile to find.

 

well its very odd, but they are working for the time being ha.... I had ordered a new dash bezel to replace my cracked one that I had removed. I guess that dash bezel was blowing the fuse. LOL or maybe it was the headlight control box that I replaced with the new bezel ha. THANK YOU for your advice!

 

Dean can you please provide the schematic for that. I also have a similar issue. It doesnt do it while i drive. Well i haven't tried it but. It does it instantly i change the fuse. If you can share the schematic that would help me greatly. Thank you!

 

Do you have a bulb under the dash that comes on with the interior lights? Might want to check and make sure you didn't accidentally stick a screw through the wire or something when you were messing with the dash.