Ok a lot to go through but ill start with my Saz 1500d wired @ 1ohm to a nightshade 18 d2, i have a 106ah marine batt up front big 3 in 1/0 with all grounds secured to chassis HU is alpine 9883 car is a 1978 ford Ltd. alt was upgraded to 100 amps from 60 (awaiting HO alt). Voltage checked before and after all fuses 14 with car on 12 with car off, previously the remote lead went out on the HU so i ran a toggle switch via jumper wire and all was fine.

The problem started after i finished the big 3 everything was going smooth at full tilt voltage staying above 13 volts then after about 10 min of play with car running amp stopped playing no protect light or anything so i check voltage at all previously mentioned points everything good. Removed toggle switch an ran a direct jumper from power to remote terminal when i did so i noticed the voltage drops from 12v to 5v at the amp, i know that the amp is not powering on because of the low voltage but the voltage only drops when the remote wire is supplied with power, sorry for the long post but i wanted to make sure i included as much info as possible plus the Kettle One has me in the mood to type lol.

You can use a switche accessory wire to power on the amp. Splice into the red wire on your headunit.

Also you might want to check all your grounds.

Hopefully somebody else will have something better to say

I have switched grounds an that seemed to work then as soon as i gave it some volume it shut off it did this on both old and new ground, i also tried the acc wire also, thanks.

Any one else?

Any good trobleshooting place to go from here would be to swap a known working amp in your system or put your amp in a known working system so you can isolate the problem to either being a bad amp or bad elecrical system in your car.

If the amp is faulty it would either need repaired or replaced.

If the amp is good you need to identify why your voltage is dropping so low it shuts the amp off- if that's even the reason it's shutting down.

At this point it's hard telling telling what the problem is. If the amp is good you would need to get a reading off the amp when it shuts down.

If it is voltage drop that's doing it it would either be alternator output or a bad ground at the amp. I suspect for some reason bad rcas could be causing the problem as well as a fault in your head unit not sending output when you turn the volume up.

I think swapping out is the best place to start.

Let me know what you find out

Ran 1/0 ground from front batt to rear all seems well, goes to show all grounds that look aren't always good.

If your car is a unibody with no frame rail to run to it can be tough. Usually a good clean body ground will work but a run to the front is probably better

Find the best ground possible even if you have to go under the car......

I had to cut my trunk floor to get my box in so i went trough the expanding foam to get to the bumper area but i had to use washers cause the hole was too big im guessing that was my prob. I should have known better. The hc2400's go in today that will be the tale of the tape.

WoW !!! 78 ford ltd. Ain't seen one of those in a while. Post some pics. I think those had frames. You grounded in front, rear(near battery), and near amps?

Dont have too many pics as of yet but im doing a build an they should be up soon, but so far i have big 3 1/0, 2 1/0 runs 1pos 1 neg, I have to find another spot to ground the 2 hc2400's in the rear. My plan is to run 250 amp mechman alt (on the way), orion 8004 on a set of 6.5 germs, as well as another saz1500d strapped to an RE MT (PSI) 18 @1.4

Old School Ride !!! Nice. Best of luck

thanks