aftermarket radio it protect when connecting subwoofer

[wawa]

I install a Kenwood kmm-100u radio. When connecting front and rear speaker directly to radio harness, it work great. But as soon I try to connect the door subwoofer to the RCA subwoofer plug, radio goes to protect mode.

testing ohms I get around 4 for each side
testing resistance, I got about nothing (.01)

What can put the radio to protect mode as soon as I connect the subwoofer?

thanks
Chris

[particlewave]

Ohms and resistance are the same thing.

0.01 ohms is unacceptable and will put the stereo into protect mode. Either something isn't hooked up right, or you have a short somewhere. Check your wiring and measure the resistance in ohms for each speaker separately, specifically the sub, and report back

[wawa]

I dont know much in electronic.

meter set on 200 ohms, I read about 4
meter set on next symbole look like ->|-, read about .01

Does it sound right?


wawa

[wawa]

damn it I think I just find out.
From the Manual:
''Selects whether rear speakers or a subwoofer are connected to the line out
terminals on the rear (through an external amplifier).''

Line out, that means the signal is not powered and need to be connected to an amp? Right?
I tought since its was lebel subwoofer, its was powered and could drive the sub directly, just like for the speaker out.

Could it be why?

later
wawa

[particlewave]

Ah...yes, you want the 200 ohm setting and 4 ohms is perfect. I believe the next symbol you are referring to is diode check and not needed for this.

Do you have the manual? Normally protect mode occurs when there is an overload of the internal circuit caused by a short in the speaker or wiring. Do you have the sub direct connected to the stereo head unit or does it go through an amp first? The "sub" output is typically designed to be used with an amp and is simply a pre-output and won't power a sub by itself. I'll check your manual for you...

Edit: yep, that's your problem. You need an amp

[thom4782]

The second symbol is where one sets the meter to test if a diode is functioning properly.

[wawa]

yes its just a pre-output.

And of course I cut the wire very short, damn me!!

thanks for the confirmation

Later
wawa