I've had this problem with another amp that I had but it was over heating because the wires weren't the right size for it. Now I have a 600 watt (I believe, could be 800) but am having troubles with it cutting out only while the car is started. If I turn the key back then it doesn't cut out at all and will turn back on if I had just had the car started and it had cut out. What could this problem be? I've checked to make sure all of my wires are fastened securely and the power is coming directly from the battery.

First of all, what size fuse? Check the amp and see what max amperage is, and insure your fuse is that size. Secondly, I suspect either a blown speaker or blown outputs. Disconnect the speakers from the amp and see if the fuse still blows. If it does, either you are hooking two wires up improperly, or your outputs are toast.

Jan 2013
1) Move wire to another same-size circuit breaker to eliminate bad circuit breaker as suspect.
Do NOT increase size of breaker or it will cause fire.
http://waterheatertimer.org/How-to-replace-circuit-breaker.html
http://waterheatertimer.org/Troubleshoot-household-electricity.html

2) Put hand on each appliance and outlet to see which ones are warm. Outlet should never be warm or hot. Replace outlet. Inspect wires for loose and burned connections.

3) If the breaker is good, then add up total watts being used by checking watt rating on each device. 100 watt light bulb is 100 watts. Big screen TV has a label that shows 300 to 500 watts. Computer has label. Space heater has label showing 1500 watts. Iron has a watt rating label. Take total watts and divide by 110Volts and this will give amp load. Total watts used = 2000 and then divide 2000 by 110 volts = 18.8 amps
Compare amp load with circuit breaker.
20 amp circuit breaker has 80% safe maximum, or 16 amps.
If amp load is 18.8 amps, then 20 amp breaker is starting to get hot, and weak breaker will start tripping.
If amp load is 18.8 amps, and breaker is 15 amps, then you are overloaded and breaker is feeling the heat, and tripping because of heat.
Solution is to reduce amp load.

4) If you have short circuit, that can also trip breaker.
Unplug everything and then plug things back in slowly to see which plug or appliance is causing the problem.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

Always match breaker and wire size:
http://waterheatertimer.org/Color-codewire.html
http://waterheatertimer.org/How-to-replace-circuit-breaker.html

Feel if breaker is getting warm.
Listen for crackling sound.
Breaker is tripping.
Move wires to another same-size circuit breaker and see if problem continues.

Check watt or amp load on breaker.
For example water heater label shows 4500 watt non-simultaneous.
4500 watts divided by 240 volts = 18.75 amps.
You might think 20 amp breaker was good in this case.
However electricians use 80% safe maximum.
20 amp breaker x 80% safe max = 16 amps.
Water heater is 18.75 amps, so install 30 amp breaker.
30 amp breaker uses 10 gauge wire.
This means wire to breaker will run cool and not get hot, so breaker lasts longer, and there is more efficiency.
Using 80% safe maximum rule protects home, reduces heat wear on breakers and breaker box so everything lasts longer.

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

A number 12 copper supply cable at the voltage is overkill for this load.

Ohm's Law states: Watts = Volts x Amps. To find Amps: Amps = Watts / Volts. This is 1500W / 240V = 6.25 Amps. Since the max continuous load for a 14 copper is 12 Amps, this size wire is the correct size.

Check to make sure the heater is in fact a 240 volt type, as if it is a 120 volt type, you are likely instantly burning out the heating element. If it is indeed a 120 volt heater, you will need to connect to a single pole 15 amp breaker and place the other wire that was on the breaker to neutral to provide the correct voltage. The load will still be 1500W, but at half the voltage, the current will double to 12.5 amps, and may cause the circuit breaker to trip after a while.

I hope this helps & good luck.

Look at rating plate on side of unit for Volts, Amps, Watts.
Volts x amps = watts.
If unit is 240Volts, then you need double-pole 240Volt breaker
If unit is 8500 watts at max power, then 8500 watts divided by 240Volts = 35 amps.

What size breaker for 35 amps?
When electricians figure load rating for breakers, they use the 80% rule.
40 amp breaker x 80% = 32 amp safe maximum load for 40 amp breaker. Use 8 gauge wire with 40 amp breaker.
50 amp breaker x 80% = 40 amp safe maximum for 50 amp breaker. I use 6 gauge wire with 50 amp breaker.
60 amp breaker x 80% = 48 amp safe maximum for 60 amp breaker. Again, use 6 gauge wire with 60 amp breaker.

How to connect wires to unit.
First of all, all outdoor HVAC units require power cut off located next to unit.
This lets the mechanic, or service tech turn power off to work on unit, even if the mechanic does not have access to main breaker box.

Next, open unit to see where wires connect.
If unit has wires, then connect both hot wires from 240 breaker to the wires inside unit. Connect bare ground wire to green ground screw.
If unit has terminals. The terminals will be labeled L1 L2. Connect each hot wire from 240Volt breaker to either one of the screw terminals. Then bare ground goes to green ground screw.

Copy following links for basic illustrations connecting wires to terminals, and to breakers, and selecting wire size.
http://waterheatertimer.org/How-to-wire-Tankless-electric-water-heater.html

If you need further help, I’m available over the phone at https://www.6ya.com/expert/gene_9f0ef4df2f9897e7

If the amp is 1200 watts at 2 ohm stable you will want to set up the speakers as parrallel and bridge the amp. That means conncect the speakers with + to + and - to -. Look at the amp connections. Usually thereare connects that look like this:
+ -
+ - + -

If yours look like this use the diagram on top. You will use the + for the left ouput on the amp to the right - on the amp. This will allow you to use all the power from the amp. Be sure to lower the gain as to not pop the speakers or amp.

buy a bridged amp with half the power of your sub (ie 1200 watt sub use a 600 watt amp) this will stop distortion at high volume get in touch when you have the amp and i'll go through how to wire it .

yes, you did a good job. Sounds like you paralled them. Which is right buuuut what size are these heaters. Add the wattage of all of the heaters and divide by 120 and that is how much current you will be using. On a 20 amp breaker you can only pull 16 amps safely. I think you will be way over unless the heaters are 600 watts each. You are allowed 1800 watts on a 20 amp circuit.

your wiring is right but did you use large enough wire to hook it up. its either not enough amps to the unit or the ground isnt making good enough contact.

start with a 50, may need to increase it if you are not using a large capacitor.
600 watts = 12x
x= 600 watts / 12 volts
x = 50 amps