Headunit Wiring - Can't Get Power to Unit

[txresponse]

I've been struggling getting my new headunit to power up, I started with the basic Power adapter for it before I started connecting the speakers.

The power harness is: Black Red Yellow Blue (So ground, acc, 12v constant, ant?)

I connected:

-Black to black

-Red to red

-Blue to blue

-Yellow to... White/Purple, then White/Blue, then combined Red + Yellow (Stereo Harness) to connect to Red (Boat Harness)

 

Battery is on, ignition is on, stereo switch is on.

What am I doing wrong? I'm trying to get the headunit to power up before I start figuring out the speaker wiring arrangement

 

Edit: The headunit before worked (Kenwood), but it wasn't a marine headunit so I got a Pyle marine headunit. Fuse is good on the back of the Pyle. Light on the rocker switch lights up so I'm assuming that has a good power supply to it.

Edited May 27, 2022 by txresponse
More details

[MLA]

Get a $20 volt meter from Harbor freight and find your ground, constant 12V and switched 12V on the boat side. 

[txresponse]

3 hours ago, MLA said:

Get a $20 volt meter from Harbor freight and find your ground, constant 12V and switched 12V on the boat side. 

This was the first thing I did I should have mentioned, I got an auto multimeter ( https://www.homedepot.com/p/Klein-Tools-600V-Auto-Ranging-Digital-Multimeter-MM400/206517333 )

Set to V~ and couldn't get a reading in the factory harness. Ground was on the battery ground. This is why I posted this because I got confused, the stereo was working prior to me cutting the wires. Unless V~ isn't to read 12v I'm hitting my head against the wall. I don't see how the factory harness would suddenly stop sending voltage - I checked the fuse panel and seems fine.

[MLA]

Test your meter and settings right on the battery. I think you are on volts AC scale. 

Edited May 28, 2022 by MLA

[csleaver]

On most meters the V~ setting is for reading AC voltage.  You need to set the meter to read DC voltage which looks kind of like V= on the meter.

[txresponse]

On 5/28/2022 at 7:37 AM, MLA said:

Test your meter and settings right on the battery. I think you are on volts AC scale. 

 

On 5/28/2022 at 9:32 AM, csleaver said:

On most meters the V~ setting is for reading AC voltage.  You need to set the meter to read DC voltage which looks kind of like V= on the meter.

Thank you both, the multimeter did default to AC so I had to press SEL to read DC. I got the unit powered up, now I need to play with the speaker wires and hopefully get those working next