amp voltage drop on start up

Greetings,

I've searched for a solution to my issue, however I can't seem to find any info that leads me in the right direction. I hope the gurus here can help me. :) Please keep in mind this is my first install of this type, so I'm pretty new to this.

My problem is that when my car is off and has sat for a while, via multimeter I see exactly 12v to my amp. As soon as I turn the car on, and turn the radio on, the amp starts up in protection mode and shuts off after approx 2 seconds. If I leave my multimeter connected, I see the voltage quickly and progressively drop from 12v all the way down to 3 volts and then it stays there no matter if the radio is on or off. The amp will have already shut off before the voltage finally stabilizes at 3v. If I turn the car off and let it sit for about 10 or 15 minutes and then check the multimeter again, it will have eventually risen back to exactly 12v. (with the car still off). If I start up the car, but not the radio, it stays at 12v. Only when I turn the radio on, will it drop.

I've checked all I know to check, like grounding and wiring. I am grounded to un-painted metal on the chassis of my car, so I believe I'm fine in that respect. Nothing but RCA cables are plugged into my amp (the amp doesn't seem to start up without at least one set of RCA's pluged in.) I'm running a Kicker zx700.5 amp. Can anyone help me determine why my voltage drops upon startup? Thanks in advance!

It sounds like your amp is grounding through the RCA.

I would recheck the ground (meter from the amp ground to the constant power wire without the RCAs plugged in and see what you get.  You can also try disconnecting the RCA cable and measuring resistance between the ground of the amp and the ground of the battery.

Thanks for the reply KPierson. I just checked with the RCAs unplugged and I get the same result.

Sadly I'm unsure of what proccess I must follow to test the resistance between the ground of the amp and the ground of the battery.  If you can tell me what I need to do to compare the two, I will get the info you need.

If you're simply wanting me to test if I have 12v at the battery during the time I'm down to 3v at the amp, I do have 12v to 14v at the battery. This leads me to believe my problem is at the amp or its wiring. If I'm misunderstanding your request though, please let me know and I'll follow whatever process you describe.

Thanks again!

I am an idiot:

Your name is misleading...you don't sound like an idiot to me. ;)  And I appreciate your help.

I have tested the power wire to another random unpainted portion of the car and I see the same voltage drop when the radio is turned on. My amp is cool to the touch and the vents are lukewarm. The power cable I am using is a "monster cable" brand cable, and the fuse is the type that is simply spliced into the cable with a rubber cap to protect it from water. It doesn't have the mounted, clear plastic in-line fuse that seems to come with other kits. I've trusted monster cable for other types of wiring, so I hope I didn't make a bad desicion there, I would hate to have to re-run another power cable. =p