Voltage issue in factory H/U harness (You should read this)

[Jessica]

Just a little heads up for you guys out there, Never trust factory wiring in your rides. Here is a good example of why you should run your own wiring to make sure you don't risk damaging your equipment

My H/U switched power wire, the one the radio actually uses for it's power source not the memory wire, will read 12.8v (car off) until I turn on the blower motor for the heater. Then it drops to 11.8v. With the car running I see 14.5 and it will drop to 13.7 with the fan on.

Now, before you start blaming my battery, note that I can turn on the headlights, roll up and down windows and whatever I want and I get no drop in voltage. This same car had a skar 1500 @ 1ohm and would only drop to 13's full tilt, no way a blower motor is pulling more current and that amp. I am using the VM-1 to check this too.

The point of this thread is to show that manufactures don't always have car audio enthusiasts in mind when they wire things. As you can see from my vehicle, they somehow managed wire it in a way that the fan effects the voltage for the h/u. This of course could cause noise in the signal, or other issues.

I'm not asking everyone to go throw a volt meter on the power lead to their headunits, but It's isn't a bad idea to test this type of thing. One can never be too safe.

I for one, will be redoing some electrical very soon.

[Quiet]

I never have used factory HU power or ground... And that is exactly why. It's not meant for transient demand and eventually you're fighting for current somewhere upstream in the power harness and fuse panel. It's not like you need anything larger than 14 gauge for HU power so it's dirt cheap to do... no excuse not to.

[hdorre]

Mine is the same way. The only factory wires I used were ACC and the dimmer iirc. I ran my own power from batt and grounded to the frame, and use RCAs lol

[Jessica]

Mine is the same way. The only factory wires I used were ACC and the dimmer iirc. I ran my own power from batt and grounded to the frame, and use RCAs lol

What do you mean, "use RCA's"?

I think you are trying to add to the info right? Saying don't use speaker level outputs?

(I hope you arent trying to tell me to use rcas lol)

[hdorre]

I meant "used" RCAs. I'm not telling you to use RCAs instead of speaker level outputs.. I personally dont care what you use