You have an extreme case of VD (voltage drop) could be caused from a weak or faulty connection or wrong guage wire on either the positive side or ground side or possibly both between the amp and battery.

Figure the power/ground wires to the amp as a hose. You wouldn't want to use a garden hose to put out a house fire because it will not supply enough flow same goes for electricity.

 

Right now it's 6g ground and 8g power with no fuse just to test it. It's hard for me to wrap my head around the fact that everything went to **** when i added a diff amp and 2 extra speakers.
Things were good with the micro 2v2 and hertz but a channel on the 2v2 ****ed up so i opted to upgrade

 

You are checking gains with a meter on AC voltage right? If it powers on and the speaker plays, it should read voltage

 

You still haven't answered Babyboy as to if you see the same issue with the engine running as well as when it's off (as it was in the video). All the suggestions of proper gauge power wires etc. aside, you're seeing normal voltage with the engine running and under load. You also seem to see normal (maybe a bit low) voltage on the battery when not under load.

If you are seeing a 10.7 with the engine off and battery under load it suggests that you need to have the battery tested using a battery tester (there is a difference from using a multimeter). I would guess it needs to be replaced.

 

The Diamond 2v and 4v amps are pretty robust and don't have to many issues. So I am thinking this may have been an ongoing VD issue powering the amp. Start at the battery and check any and all connections going to the amp.
A poor connection will show battery voltage until a load is put on the system and then the voltage will drastically drop.

Install a good new amp kit to eliminate any questions on any used wires that may have a break under the insulation that can not be seen.


Use the K.I.S.S METHOD (keep it simple stupid) (no offense to the OP) it is DC voltage and flows in a circle from storage device(battery)to load (amp)and back to storage device.

Start with a good know battery. If the bike starts normally and battery voltage recovers after starting I would suspect the battery is good. But when in doubt have it checked out.


Start from the battery and work your way to the amp checking voltage at each and every connection with the amp unhooked.
A faulty connection will show battery voltage until a load is put on the system and then drop drastically.

 

Just ordered all new 8g power and ground. It should be here tomorrow. Ill remove the tank and have it ready to reinstall the new wires.

 

I misread the voltage readings done by OP. I agree it does look like VD (voltage drop, not STD). I also agree following the K.I.S.S troubleshooting method is the best way.

While erratic readings will happen with a poor connection I'd still test the battery as OP did not see the same drop with the motor running (takes 2 seconds and he's already at the battery).

Here's a decent article from Fluke that adds a bit more detail to the suggested troubleshooting process.

 

Not that what BabyBoy and Hamah stated isn't very important. It's surely an issue. Don't however glaze over what was already posted. If you are getting 0 voltage at the speaker connections, make sure your multimeter is set to A/C voltage when testing amp output.

 

I must have missed switching to ac when checking the speaker terminal at the amp. I was stumped as to why everything was working but i the gains increase didn't make the meter move. When i did this with my other amp everything went fine but apparently i did it right that time. My new wires will be here today. I already have everything torn apart amd ready to run the new wires.

I guess my las question is my in line fuse. Its a 20amp but I'm not sure of the wire gauge. Does that even matter? It was ran with the fuse end connected to the batter and crimped to the power at the other end.

Other than all that the last task is putting water resistant fabric on the lowers. That stuff will be here Tuesday.

 

I've been battling covid. Ive had a ton of issues with the bike. It seemed like everytime i did one thing something else needed attention. But its finally hooked up. I was able to get it tuned damn close to what i needed. It was only like an 1/8 of a turn on the gain but even with everything set to flat I'm still impressed. All i have left to do is put it all back together and put water resistant fabric on the lowers. With the new power and ground mu voltage was the same at the battery and amp BTW.

Thanks for all the help guys