Diff. between a zapco reference 350.2 and a reference 350

check and see if you have been losing coolant . I'm betting on a bad head

Go to this link and see page 47

http://www.zapco.com/files/Download/DCRef.pdf

i got a wiring paper that comes with the peq plug,its not a manual but it shows how to wire up a zapco peq

check your settings on your stereo and the amp make sure you have changed to 1 ohm on the amlifier for a briged connection to a subwoofer and change from lpf to hpf on the amp there should be a switch.

Storing as in Distortion? If that's the case lower the output gain from your amp until it is suitable to you ears. It might be all the way open, besides this should be adjusted system to system.

If the amp uses TIP35Cs and TIP36Cs, those will be the output transistors. Measure the resistance between legs 2 and 3 for each of the output transistors. Do any read near 0 ohms?

If you're new to repairing amps. The following page should help.
http://www.bcae1.com/repairbasicsforbcae1/repairbasics.htm

the basic wirings are for inputs, power and for the speakers (front and rear). If you open up the device and trace the wires to the fader control (electrically), those are for the speaker outputs. The power supply line is much easier to locate through the power capacitor..maybe. watch out for the remote wire if it has one (this triggers the device to power ON). gudluck!

Hi this is tech crazy.I find this to be your apt solution for the problem posted

Check your ground and make sure it is properly grounded ....it needs to be a very clean paint/gum free area tightly bolted.  Next Check and make sure you are recieving your 12 volts (not running)  13 (running)    by placing your test leads from positive to ground...... then make sure your power remote from your head unit is putting out voltage. 

Go here first http://www.zapco.com/ Good Luck