99 ML320 brakelights

COULD BE LOSE OF GROUND OR BAD BULBS OR CHAFFED WIRING

My first guess would be a ground problem.
The headlights and tail lights are controlled by the same headlight switch, but the brake lights are on a totally different circuit.
You may have to get a shop manual to get the wiring diagrams needed to troubleshoot the circuits if the ground connections are ok.
The lights involve the body computer and other components.

Okay, these are hard to find. I assume you have no problem when you do not have the Tailights on? This would mean problem could run all the way to rear taillights.

But if the problem is not related to putting power through the wires to the taillights it is under the dash area. You would have a short from the power supply to the lightswitch. You have a Relay for the lights in the Powerbox.

Go to Autozone.com Website and register your vehicle for a free wiring diagram and Powerbox layout.

You can then see for yourself about how the dashlights are grouped with the taillights. You could have a bad Relay.

Look at how the taillights get their power and this will show you a color/coded path from the front to rear of your car. As I said earlier, it is important to know if the lights only short when they are turned on by the headlight switch.

If they short out all the time, regardless of the headlight switch being on or off, then the short is more towards the front, between the dash and Relay or the Relay itself.

Use the built-in cutoff points as a way of eliminating the shorted part. The headlight switch is a cutoff point. Power rearward is halted with the except of the Brakelights. If the Brakelights work fine, the bulb sockets are probably grounded properly.

If the fuse pops with the headlamps off, the power is not going rearward and you are okay.

i think their is some wiring problem and to fix the problem you need service and repair manual along with diagram so that you can locate and fix the problem easily by your self and you can get the manual from the given link http://toolsnyou.com/

check the switch at brake petal under dash it sometimes comes lose or out ov adjustment u will see it under dash folow petal up 2 it

check for bad brakelight switch on the brake pedal under the dash,but on the brake pedal rod,will be a switch that has a pluger that pops out when you apply the brakes,check to see if it's plugged in. other than that,just replace the entire switch,yhey do go bad often enough.

I may have a ford wiring book for escort. $5 plus $2 postage. Let me kno wif interested and I will check for it.
tailights and instrument panel lights are on same circuit. I suspect a fuse. Go to motorcraft.com and see if they have an owner manual with fuses identified.

It was a loose ground for my trailer wiring harness.

check the wiring from the tailights back to the fuse panel, it sounds like an open connection. if i recall correctly check under the dash on the drivers side near the fuse panel for a bunch of wires in a bundle and look carefully for a wire or two that are cut/shorted/or seperated, you can also check under the drivers side kick panel by the hood release.

sometimes they are seperate bulbs i would check all the bulbs if there all okay then u might have a short somewhere