justin8989

Hey just curious i ran into this problem as well. Checked all
my fuses with the little checker thing(sorry i dunno what its called) they were all good. Tail LPS kept blowing everytime id turn on my lights. Unplugged all the orange wires from the back of the head unit replaced tail lps fuse and it stopped. But still no sound to any of my speakers, no wires touching, checked the fuse in the back of the head unit too and still good. I follower all the advice given in this thread and im still lost. My tails, brakes, and dash lights all work now but the head unit dosnt make any sound to the speakers still. Btw i have them directly wired from the speakers straight to the head unit, no stock amp in the back, just using the head units internal amp. Ran for a few days with sound, but everytime i turned on the lights the head unit would restart than all of the sudden it stopped working all together so i did everything this thread said....now im confused what to do from here. Thanks

WhiteBird00

iTrader: (4)

First of all... factory head unit or aftermarket? If aftermarket, was a proper wiring harness adapter used for installation or were the wires just spliced together?

I ask because the orange wire reference would mean different things in either case. The orange wire for a factory HU is battery power to maintain memory and clock. It has nothing to do with lighting. Both orange wires (one plain and one with white stripe) of an aftermarket HU should never be connected at the same time - use one or the other. The plain orange wire is for variable power input from the dash lights so that the HU can dim with them. It would connect to the grey wire in the factory harness. The orange/white wire is for simple on/off (dim/no dim) operation... it dims the HU lighting by a set amount when the lights are on. It would connect to the brown wire in the factory harness.

I suspect that the problem is either cross connected wiring for an aftermarket head unit or a bad head unit... most likely the wiring.

bearwolf70

To respond to some of these threads I was have the same issue I have a 04 Ford F250 I took out the OEM radio and put in my Jensen Radio and I had the Ford adapter on it, and the last 2 fords I had, I didn't have dash lights I was getting frustrated with this happening on my new truck, I read to not have the orange wires hooked up so I took and cut them, still no lights, so I checked all my fuses and seemed ok, until I notices I left my lights on and there was no dinging like before to remind me, so I started looking at my fuses again, and wouldn't you know, it was a fuse, for me it was fuse 17 exterior lights fuse, it was blown, I changed it and I got my dash lights back, my fog lights back and my brake lights. Hopefully this will help, after reading every ones comments I was able to narrow it down to a fuse so thank you. and hope this helps to.

1999nbmZ

Don't forget that when checking the fuses for parking light, tail lights, or dash illumination, that you want the lights turned on to check.

If the lights are off, then the wire feeding the bulbs will be at 0 volts. Since you have no voltage on the positive side of the bulb, then the ground for the bulb will back feed, giving you 0 volts on the output side of the fuse. If you hook a meter up to both 'pins' on the top of the fuse you will see 0 volts on both sides. Hence a blown fuse can still read 'good' if you're using the resistance setting on the meter.

Either pull the fuse and test continuity across both terminals, or switch on ignition and light switch, and test for voltage on both of the nubs on the top of the fuse.

And just as WhiteBird stated, sometimes fuses will blow, without looking blown. I've even had some test good in my hand, but not be able to pass any power. Very rare, but does happen. Those would be tough to spot without reading voltage drop across the fuse while it's in place.

Glad that you got it straightened out though, post up if you have any questions.

WhiteBird00

iTrader: (4)

You would only get back feed through a bulb when there are multiple bulb circuits that share a common ground that is missing. For example, if your tail lights have their ground disconnected then applying power to either the tail light circuit or the brake circuit will cause power to back feed into the other circuit because they have no ground to flow to. As long as there is a good ground, current will always flow the path of least resistance - directly to ground rather than through a resistive bulb filament.

Besides, the light switch is after the fuse in the circuit so even if there was back flow, it wouldn't reach the fuse with the switch off (the circuit is interrupted at that point). In this case, because the TAIL LPS fuse has constant (battery) power, a simple test light will tell if the fuse is good - with the fuse in place, if there is power on both legs then the fuse is good, if only one leg has power then the fuse is blown.

James Fuller

Dimmer fuse keeps blowing but only when i turn on the lights. All bulbs n fuses are good but the 5amp fuse blows when i turn on outside lights and my gage lights dont work but gages do work. I replace all fuses and everything works but my gage lights for night driving and fuse only blows when i turn on my outside lights.

WhiteBird00

iTrader: (4)

What kind of vehicle? If it's a 4th generation f-body then the fuse would only blow when the headlights or parking lights are on since it has no power otherwise. Power for the dash illumination flows through the TAIL LPS fuse to the headlight switch to the dash dimmer switch/rheostat then through the IP DIMMER fuse to the individual bulbs in the dash, console, and doors. Many newer vehicles have their dash illuminated during the day without the headlights or parking lights on but 4th generation f-body dashes are dark unless the lights are on.

In any case, when you have a fuse that blows whenever it's used, you have an electrical short someplace downstream in the circuit. That could be a wire grounding out on something metal or an electrical load (device, bulb, etc.) which has failed and is drawing too much power.

Marla

After countless wasted hours of trouble shooting I went to the dealership and just asked for help and their top electronic guy told me the same thing . So I bought a multi pack of fuses and just started swapping them out with no real hope it was worth the effort but when I turned the key over and all my lights , bells ,and whistles worked again . I was disappointed in myself for not trusting all the knowledgable people on these forums!!! !!!!!!!