My mtx TNA251keeps going into protect mode after i put the speaker wires in

Mtx 801

Check the speaker wireing that it is not off somewhere ,or pinch.End shorting out. If all that is okay. It is not wired up properly to the sub or what ever speakers you have hooked up to it, Or you don,t have it set up (Poperly) They do not go into the protect mode For nothing,Unless you are trying to wire up your sub or (Speakers) To lower ohms then what it is stable for.If that is the case your lucky that it hasn,t went up in smoke yet,End that is not covered buy any manufacturs Warrenty,

on some amps there is a duel light. red and green usually. red means it is in protect mode or you didn't hook up your remote wire. if in protect mode, it could mean a number of things. did you hook it up with speakers and everything?

you have the speaker wires wrong + to - o - to + put make shoore speaker wire is in place .

http://www.mtx.com/caraudio/archive/NDM185.pdf .... go to this link for more help, it is the owners manual

wrong wiring for the speakers. to low of an ohm load so amp is going into protect mode. rewire to 4 ohm stereo.

Looking at alot of the unsolved FixYa problems - I can see alot of "My amplifier is going into protect mode - How do I fix it?"

There is no catch all or simple answer. Troubleshooting steps must be taken to determine what is causing the problem.

It is one of 3 things....

1. Impedence under rated value or Thermal Protection.
2. Short to ground in wiring.
3. Internal Component Failure.


One of the more confusing things with a car stereo can be when the amplifier goes into protection mode. One minute it's working and the next minute it's not. Here's a brief troubleshooting method that will hopefully help you if your amplifiers ever go into protection.

1. Try to determine the cause. Amps can go into protection mode for several reasons. Knowing what happened before it cut out can help determine how to fix it.
Did the amp not work as soon as it was turned on?
Did it happen after blasting for hours (may be thermal overload and it needs to cool)?
Did it cut out after you hit a bump (a wire connection may have come loose)?

2. Tear it down. Get the amp down to it's most basic state. Remove all of the speaker wiring and RCA wiring and leave only the power, ground and remote leads connected. If you still have a problem in this state then either your amp is defective or you may have an installation problem such as the amp touching metal.

Remember that an amplifier should only be connected to the vehicle through the power and ground terminals. Mounting the amplifier to the metal of the vehicle, including putting the mounting screws into metal, can cause problems for your amplifier.

Always mount the amplifier to a non-conductive surface. An easy way to accomplish this is to mount the amplifier to a wood board and then mount the board to the vehicle.

3. If the amp is OK in this torn down state keep adding the other wires back on until you find what causes the problem.
Add the RCA cables first.
Then add the speaker wires one at a time.
If the speaker wires cause the problem then they are probably touching metal or have a blown voicecoil.
Check to make sure that a speaker wire isn't being pinched somewhere between the amp and the speaker.
Also check that the speaker wire or speaker terminals aren't touching the vehicle metal near the speaker opening.
Rear decks and door panels can easily touch unprotected speaker terminals if not properly installed.

If the problem starts occuring when you connect the subwoofer wires to the amplifier you may have your subwoofers wired at too low an impedence. First check the spec's on your amplifier to make sure what kind of loads it is stable under. Then check the wiring configuration to make sure that your load is not too low:

If you believe your amplifier is defective contact the manufacturer first. Many have flat repair rates that are very affordable and cover parts and labor.

However local repair shops may be cheaper if it is just a small repair.

Compare the manufacturer's repair rate to that of a local shop. If you don't know the reputation of the local shop it may be better to send it to the manufacturer who will have working knowledge of the amp and parts readily available.

Thanks for using FixYa - a 4 THUNMS rating is appreciated for answering your FREE question.

double check your wires aren't shorting out or power or remote wires aren't grounding. check if speakers are blown with nine volt battery

Two things, a problem with the speakers, or the amp is toast. If there is a short is the speaker, wire touching, bad voice coil, the amp will go into protect. I have also seen many, many MTX amps that go bad, and just stay in protect. the easiest way to check, is to unhook the speaker wire from the amp, then power it up, if it still goes into protect without a speaker hooked to it, you have a bad amp. Hope this helps.

this is a signal crash either your speaker wires are crossed (wrong wiring phase) or your RCA jacks need replacing also it could be inside your amp the solder lines may have fused. If after checking and replacing wiring problem persists return to MTX for repair.