Question about MTX Thunder TA7801 Car Audio Amplifier

1 Answer

Amp is not coming on

All the wires are hooked up and i just replaced and power wire because it was a 10 gauge to a 4 gauge. before i changed wire it worked but i blow a fuse witch caused me to change wire size. what would cause my amp to stop working now when all i did was change the wire and fuse?

Posted by on


1 Answer

  • Level 1:

    An expert who has achieved level 1.


    An expert that hasĀ over 10 points.


    An expert whose answer gotĀ voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 15 Answers

The fuse may not be working, you could try a larger sized one, also if you have the old power cable try it again with a larger fuse in place, if it worked before its likely to just be the fuse wasnt big enough, check all the other connections are in the right place, if they all are and you know the amp hase worked before then it could only realy be the fuse isnt big enough or the power lead is faulty.

cheers, adam

Posted on Nov 18, 2007


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

A 6ya expert can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
The service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.
Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

How to hot wire fuel pump for 97

How to
Hot Wire Your Fuel Pump With a Relay in the Trunk

Terry Littleton -

You Will Need

Get 15 ft 10 gauge wire, 3 ft 14 gauge wire, and a Bosch 4 or 5
prong 30 amp relay. Any place that installs car alarms should have a Bosch
relay. Get a heavy 10/12 gauge wire 30 amp fuse holder. They can be found at
auto parts stores and come in the old glass or new plastic spade type fuses.
Make sure it is heavy wire and not like most that use like 14/16 gauge wire. You
will need 2-10 gauge butt connectors, 1-10 to 16 gauge butt connector, 2-10
gauge female spade connectors, 2-14 gauge female spade connectors, 1-10 gauge
and 1-14 gauge ring connector. Soldering gun, wire


  1. Disconnect battery. Put a ring connector on one end of the 10
    gauge fuse wire and attach that to the post at the rear of the alternator. Run
    it over to the front of the drivers side valve cover and attach to a piece of
    ten gauge wire that you will run to the back of the car. I put mine inside the
    car and it was actually easier.

  2. Run it through the hole next to the powermaster where all the
    wires go through the firewall. I routed it over behind the emer brake pedal,
    down behind that kick panel, took off the sill plate and put it inside the
    plastic wire protector (it does come open, just a pain to figure it out). Take
    out back seat and run it from sill up to opening that goes into the trunk. There
    are other wires that do the same thing, just follow them. Bring wire down to the
    hinge support. There is already a hole right there to put a bolt and nut through
    to mount the relay. I had a radioshack relay but it broke so I got a
    and it seems a lot sturdier. Good choice.

  3. Just a word of caution. Follow the wires down to the side of the
    trunk floor. The copper colored wire is the one to attach the trigger wire to.
    It looks like bare copper wire but is actually coated. The coating is so hard, a
    regular scotch lock wouldn\'t make contack on mine, so I cut out a half inch
    section of the insulation and soldered the trigger wire (a small piece of 14
    gauge from the relay prong 86) to there. I wrapped it in tape and put corrugated
    wire guard over it.

  4. The ground wire from the relay (a small piece of 14 gauge from
    prong 85) can go to the bolt hole you use to mount it to the hinge support. Just
    clean off the paint first. Then hook up the 10 gauge wire from the alternator to
    post 30 on the relay. The remaining prong on a 4 prong relay is the "Power Out"
    that will feed the alternator voltage to the pump(s). If you have a 5 prong
    relay the two remaining prongs should be labeled 87 and 87a. One is the "Power
    Out" when relay is energized, the other supplies power when the relay is not
    energized. Use a test light to determine.

  5. Run the remaining heavy gauge wire from the "Power Out" prong
    (when energized) from the relay through the rear of the trunk to the fuel pump.
    Notice the plastic cover over the BIG rubber grommet that takes all those other
    wires from the trunk out under the back of the car? Forget about getting your
    new ten gauge wire through there. Just drill a hole big enough to run the wire
    through covered with some corrugated protector. I put mine right next to the
    rubber plug. Then run the ten gauge wire to the pump.

  6. The 3 wires going to the sender/pump are Black-Ground,
    Pink-Fuel Level Sender, and Brown/White Stripe-Fuel Pump motor. Cut the
    Brown/White stripe wire after the connector on the fuel pump side and attach the
    new ten gauge wire. Leave enough to reconnect stock later if desired. Put a butt
    connector on the old cut wire so it doesn\'t short on anything. I wire tied stuff
    up neat and used wire protector. If you have an external pump, you can run
    another piece of 10 gauge to it for power from where it splices into the
    original pump wire.

  7. Now the wire coming through the firewall goes over behind the
    drivers valve cover and along the back edge of it under the EGR tubing in wire
    protector and splices into the other fuse wire from the

  8. When you turn on the ignition, you should hear the fuel pump
    prime. The only problem I had was in the connection of the trigger wire to that
    copper colored wire in the trunk like I mentioned above.

Hope this isn\'t confusing. I did it this way to keep things neat
in the engine compartment.

Jun 26, 2013 | Cars & Trucks

1 Answer

Need to hook 230 volts to car lift

this is 2 ---110 volt power feed lines & a neutral ( ground ) 3 wires all together , a second redundent ground won't hurt -----the same power feed as a stove or dryer .make sure to use at least 10 -- 8 gauge stranded wire / check the product requirements ---thicker wire ( smaller gauge number ) for more amprage or loner distance...will also need two 15--30 amp circuit breakers///// check specs......

May 26, 2011 | Air Tools & Compressors

1 Answer

Have problem with the trailer hook-up wires. Have 7 wires just need to hook-up to the 4 wire prong. Which wires do I use? Have power to the smaller wires but not the big gauge black or blue wire. Only 2 of...

most of the wires are only for lights & will only work as such. the best thing to do is go to you local car parts place & pick up a converter that plugs into the 7 wire connector & changes it down to the four wire. It's usually less than $10 & saves a lot of time.

Jan 15, 2011 | 1993 Jeep Grand Cherokee

1 Answer

Jensen CD-510K hooking a 200 watt amp to it.Need to know what wires need to use to hook it up

rca cables for audio and a remote wire. just plug the rca cables into the plugs in the back of the deck and the remote wire (i suggest buying a thicker (speaker wire size) gauge wire since it allows you to get more power out of the amp) to the blue remote wire coming from the deck. you will also need an 8 gauge power wire (12 inches to 12 feet depending on where the battery and amp are) and an 8 gauge ground wire (no longer than 24 inches).

Aug 18, 2010 | Jensen Car Audio & Video

1 Answer

Jl audio 1000/1 low voltage -keeps shutting off at high volume

You should definitely upgrade the power wire to the sub amp to 4 gauge -absolutely your choking your amp its starving for current-poor thing is starving !!!!!!!

Apr 16, 2009 | Jl Audio 1000/1 Car Audio Amplifier

2 Answers

Installing The Subwoofers to the amp... etc.

You should go with a 4 guage power wire kit. If your amp is going in and out
at high volume than that is your problem. 8 guage will work but, if you want
the proper current which is your power from your battery, going to your amp
than I would recomend the 4 guage amp install kit or just the main power
wire coming from your battery. If you would like contact me and I will send you
to a very good sight with all the info you will ever need for car amplifire installation.

Apr 21, 2008 | Insignia 600W Bridgeable Amplifier with...

1 Answer


Ideally you would use 1/0 gauge power and ground wire for the amps, and use power distribution blocks to reduce it to 4-gauge for each amp. Any smaller wire would be less than ideal for that much amp power.

If you're buying a power wire kit, it most likely won't have a separate distribution block for the ground wire (usually they have separate ground wire for each amp or one piece that's long enough to cut and have wire for both). This is fine, but you should look for a kit with at least 3 feet of ground wire per amp - any shorter and it's a struggle to mount the amp close enough to a ground point. As above, the main power wire to the battery should be 1/0 gauge.

Lastly if a 1/0 gauge kit is not available, 2 separate 4 gauge kits will work, however that's obviously a lot more wire to run and conceal.

Feb 21, 2008 | Car Audio & Video

1 Answer


Hi jimmyjames,


How do you have the wires hooked from the sony reciever to the inputs on the mtx? 

 Sounds like your Remote wire is way too big. it should be 14 guage.  It only sends a low voltage low amp signal.


Another thing that could be messing up the sounds is the routing of the wires.  you should have the power supply wires separate from the Audiop signal wiring.  Power should run down the Driver side and Audio down the passenger side.


When you answer I may be able to tell you more.


Oct 19, 2007 | Car Audio & Video

5 Answers

Amp runs with no ground

One thing is take the screws out that you have used to mount it. Obviously you have drilled into bare metal. The path that you have created for the ground was not designed for that kind of current which would explain some of the heat. It warns against doing that in the manual. I have this amp myself and it heats up and cuts out all of the time still. I do not believe it is a power problem. I have a 5 Farad cap. Make sure your main ground for your car has a big enough gauge wire and also, if you can afford it, buy better battery terminals.

Sep 20, 2006 | Kenwood KAC-9102D Car Audio Amplifier

Not finding what you are looking for?
MTX Thunder TA7801 Car Audio Amplifier Logo

Related Topics:

82 people viewed this question

Ask a Question

Usually answered in minutes!

Top MTX Car Audio & Video Experts


Level 2 Expert

150 Answers


Level 3 Expert

77939 Answers

Mark Skinner

Level 2 Expert

77 Answers

Are you a MTX Car Audio and Video Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides