Panel fuse blowing immediately with radio plugged in

Hi, I have a 1997 tacoma that i just bought and the backlit lights on the dash and climate controls do not work. I checked fuses and the only fuse that was blown was the 10amp in the engine compartment labeled as “Panel”. If I replace the fuse, it blows immediately.. If I unplug the aftermarket radio, the lights work and fuse doesn’t blow.
Any ideas?

 

Sounds like a wire is crossed or shorted to ground...somebody will chime in with a wiring schematic

 

That’s what I am lead to believe I just have zero idea where or why. Any help is appreciated

 

Start with the wiring on the aftermarket radio . Were the lights working before you bought it?

 

I’m sure they were at some point, but they weren’t when I bought it. I’ve been looking at the wiring on the radio, and the constant power wire has constant power, the acc power wire only comes on with the key on, and the ground seems to be grounding out just fine.

It is a BOSS Audio 455BRGB stereo.

The wiring is pretty jerry-rigged. I believe the brown is ground on the factory wiring, that wire is spliced up above the loom around the area of the vents. Then that new end of the wire is red, goes down the loom, out to the radio and is hooked up to the ground I think.

 

Why don't you just get rid of the aftermarket radio and buy a new one of your choice with the wiring all intact. Should solve the problem.

 

Well If I could save some money, I’d prefer that route. I also am not sure if the issue is in the radio wiring itself.

What wires could have gotten crossed in the installation that would cause this issue?

 

Have to pull the unit and mess with it.....test with inline fuse or bulb hooked to 12v supply..

You can replace w/new $40


Boss Audio 1-DIN Bluetooth Car Stereo Digital Multimedia Receiver *455BRGB | eBay


How much is your time worth.....

have to eliminate one by one....starting with simplest

 

Did they cut the factory wiring and splice in a new harness connector for the aftermarket radio?

If that's the case, that's where I would start. Get a pin out for the '97 and the radio and start over.

 

The factory wiring looks to be cut and spliced several different times from deep down in the wiring. That’s why I’m saying I don’t know how much good a new stereo and wiring would do if I don’t know what wires are which, even without the current plugs spliced in. If that makes any sense

 

Here is what I am dealing with

 

I will just tell you how my wires are hooked up. These are all of the wires BEFORE the wire that goes into the plug. This is as far back as I can see and trace them.
Each “>” representing a butt connector

Red > Red > to wire into accessory power plug
Blue/Yellow > Red > Yellow > to wire into constant power plug
Red > Black > Black to wire into ground plug

 

The red wire on the right of the picture has been pinched from the looks of it . You might wanna start looking into those butt splices. Some weren’t properly crimped and they taped up the exposed wire.

 

The crimped one looks like it would be the Accessory power wire. The accessory power seems to have to no issue. I removed all of the electrical tape and the crimp connections look okay, no exposed wires

It does not blow the fuse until the headlights are turned on. But if the stereo is disconnected, the fuse does not blow when the lights are turned on. It does have aftermarket headlights

 

I wouldn't waste a single second more trying to reverse engineer that mess. Cut it all off to back to the factory wires and rewire the aftermarket harnesses.

Get yourself some good wire crimps. Don't tape things. Better would be solder & heat shrink, but I'd get things working before sending it on that.

 

Does anyone know if the factory radio had lights that were controlled by the panel dimmer?

A girl I dated in high school had her father install a cassette player in her early 80's Pontiac 6000. In those days, GM's came with three plugs to the back of the radio, for the most part. One for power, one for the fronts, and one for the rears. The power plug had a yellow, black, and grey wire. The yellow was 12V accessory power. The black was the ground. The grey was the panel lights, so the display on the radio could be dimmed with the panel lights. Her dad grounded that grey wire by connecting the black and the grey wires from the GM plug before the radio, and tied that to the radio ground. Her panel lights never worked until I disconnected the grey wire, and wrapped it up in a wire nut. Her aftermarket radio didn't support display dimming from the panel lights. The display was on when the radio was on; you couldn't dim it.

My guess would be that you're suffering from the same affliction. There is probably a lead from the panel (factory wiring) to support dimming the radio display lights when the headlights / marker lights are on.

With the radio disconnected, replace the fuse. Turn on the car (acc, on, whatever). You advise that your panel lights work with the radio disconnected. Measure voltage between each connection on the radio plug to ground. Then turn on the lights. Measure again. One of those wires that was reading 0 VDC should now be reading something else. That's your guy. Disconnect him from the harness. Your radio may not support having its lights dimmed from the panel. It's probably shorting to ground.

 

There’s another place to look for a bad connection if it’s popping the fuse when you turn the lights on . Electrical gremlins are a pain to trace down. But it’s gonna be something simple like a skinned wire grounding out.

 

This was my initial suspicion after doing some research. But I can’t find any additional wires. The fuse still blows with only the power plug plugged into the radio without the speaker wires plug plugged in. I just checked every wire on the power plug which are only 3. Constant, accessory, and ground. All seem to read the correct voltage as they should

I just found another spliced wire, it looks like a black and white wire. White with black stripe

 

Do you have a multimeter? If so set it to ohms or continuity, clamp one probe to ground and start looking for wires with no resistance to ground.

also, would like to echo the above sentiment about just redoing it, that’s a mess

 

Does this help sort out the spaghetti?

https://www.tacomaworld.com/threads/1997-tacoma-wiring-diagrams-needed.495362/

The panel lights / dimming circuit interfaces with everything... Looks like you need to see where that Green-Red wire connects to...