Thread: Any car/electrical experts out there?

OK, I'm having a situation here with my Toyota Camry. Basically, the fuse to the instrument panel blows instantly when I start the engine.

I installed a CD player a few months back, and the fuse blew for the first time shortly after that. I replaced it, and it was fine for several months.

This morning the fuse was blown. I bought more, and blew two instantly.

The radio still works, even with the fuse out, so I'm not sure that the CD player is the problem. It's on a different fuse, apparently.

Any suggestions as to where I could even start diagnosing this thing?

Josh

Generally,auto electronic accessories have more than one source of 12V DC power. This is a constant ON 12V source-so that things like station presets aren't lost everytime the unit is switched off.There is also a "switched" 12 volt source that may energize high current draw items like stand alone amplifier's or disc changers.

There is also a 12V tap going to the vehicles instrument lights-so that when the cars lights are on the radio indicators come on and can be dimmed with the rest of the dash.

Without a wiring diagram-all is speculation. Blown fuses are usually caused by wiring "mistakes". Damage could have been done to an adjacent circuit by accident. Trouble shoot your power sources from the unit back to the power source and I'll bet you'll find an OBVIOUS issue. Good Luck!

One thing I can tell you is that you have a short in the system. I would start tracing the harness from the beginning up to the instrument panel and also the c/d player. Somewhere in there there is a short.

Disconnect the cd player power and see what happens.If it works you have found your source of the problem.

You may be drawing too much current. Circuits have so much current thru them and fuses correspond to that rated current. if you put an additional source in there you go over the current rating of the fuse. That is just a thought.Don't go and put a larger fuse in though. That could just create more problems.You might need to find another place to connect your cd player.

Edit:Re-reading your post if the fuse is out and you still have power something is defintiely connected wrong. Try connecting the cd player again and make sure you follow the directions exactly as stated. You should not have bypassed the fuse.

i had a very similar situation when i put my CD player in my truck and i finally figured it out. there was a wire that i attached to the ground wire on the radio. my thinking was that i knew which one was the power so the other must be the ground. what is really was was the wire to control the dimming of the panel when you dim your dash lights. so i just grounded to the frame and left the dimmer wire unconnected. it solved everything.

plus my dad (who has been a motorcycle mechanic for 25yrs) laughed at me for a good while. hope that helps.

If the CD was installed fairly recently then there is a good probability the problem is there.
If the CD worked for a while then you probably had it wired correctly or close to it.
If the fuse is now blowing instantly when you start the car then it's probably a dead short that wasn't there before.

First disconnect the poiwer to the CD fairly close to the CD. If the problem goes away then it might indicate a short in the CD case itself. If the problem persists I'd then start at the CD player and trace the power wire (not the ground). Look for connections that have come loose or exposed and maybe are shorted to surrounding metal. It may not be a connection where the wires were spliced. It could be where a wire was run through a metal hole without a protective rubber grommet and has now worn through the wire insulation. It could also be other wires in the vicinity of the CD wiring that were pulled apart or abraided as the wiring for the CD was run. The fact that it blew a fuse a while ago after the CD installation might indicate that the problem existed then. Maybe an exposed wire that's very close to metal. Driving or whatever bumped it to blow the fuse then and now it's shifted a bit to be in constant contact.

Then again, it might not be the CD at all... but that's where I'd start. Good luck.

Thanks to everyone who gave suggestions. I pulled the CD player out this weekend, and I had forgotten what a mess things were back there. The previous owner had installed one of those CD players that sits in the trunk, and it looks like they opted for a really weird setup.

The power/ACC wires were spliced into the factory harness, but not where I would have expected them to be. The harness on this model Toyota is split into two pieces, one that handles the power, dimmer, ground, etc. and one that seems to be primarily for the speakers. The wires for the CD player were connected into the speaker portion.

I disconnected those wires, pulled out the antenna switcher they'd stuck in there, taped up some loose ends, and put the whole thing back together. It hasn't blown any fuses yet, so I'm hoping I fixed whatever the problem was. The lights on the dash also seem brighter, and I'm wondering if the old setup wasn't sucking power away from them somehow.

Thanks again,
Josh

i'm glad you got it figured out. it is always interesting to see how other people wire things in eh, doesn't always seem like the easiest way to do it.

wiring in cars is just another reason why i love my motorcycles. there is just sooooo much that could go wrong in a car and so many places to look. motorcycles (for me anyways) are so much easier to work on and everything is accessible (i know there are exceptions). i know the new sport bikes have some pretty complicated and expensive electronics also, but they are still nothing compared to the new cars. just my opinion though.

It had to be the way it was wired. I am glad you figured it out.