Amp Not Turning On!

[calebkhill 10+ year member]

Update:
Now I have a **** "magic amp" that will turn on without the remote wire connected to it... What the hell! It's the Kenwood KAC-8405 that's doing this...

I think I read a while back where someone had an amp that the RCA was causing problems with the remote turn on. Not sure though, it was a while back.

 

[keep_hope_alive Premium Member]

some amps have an "auto turn-on" feature when it senses a signal on the inputs.

you can use a relay to increase remote turn-on current capability.

 

[Preston019 10+ year member]

some amps have an "auto turn-on" feature when it senses a signal on the inputs.
you can use a relay to increase remote turn-on current capability.

I've read that somewhere too, but mine comes on right as I start the car and the head unit is off and nothing is playing. I also noticed that, when I first installed my second amp, this 8405 didn't always come on the first time I started my car; I would have to turn it off then back on. Also, I don't have RCAs as inputs into the 8405, it's just speaker level inputs from a converter.

I think I'm going to go behind the head unit and find a new wire to splice the remote wire into.

 

[RSDXzec 10+ year member]

I figured out that the remote wire isn't getting enough voltage for my X500 amp. It's only getting like .16 volts. But what's weird is that my other amp, a kenwood KAC-8405, is turning on with just 0.16 volts to the remote wire. I have the remote wire connected to the remote wire behind the head unit and it runs from there to the 8405 amp then I have a jumper wire from the 8405 to the X500 and only the 8405 is turning on. Sometimes, not always, the X500 will turn on, and sometimes it won't. I don't know what to do; I know the X500 works because it'll sometimes turn on and I've ran a jumper wire from the battery wire to the remote connection and it'll turn on.
How do I get more juice flowing through the remote wire?

your remote wire must be grounded at some point if its only getting 0.16volts through it.

I had a similar problem recently, I had my mono amp out and the remote wire flying around in the boot (power wires were disconnected from the batter), one day i turned a corner and it slid over to my grounding point and shut off my 4 channel amp since I have both signal wires in parallel to each amp.

I was almost convinced I needed a new amp but then I realised what happened lol

btw when I measured the signal wire I was getting around 0.34V when it was grounded (not my official grounding spot just random metal connected to it)

 

[Preston019 10+ year member]

your remote wire must be grounded at some point if its only getting 0.16volts through it.
I had a similar problem recently, I had my mono amp out and the remote wire flying around in the boot (power wires were disconnected from the batter), one day i turned a corner and it slid over to my grounding point and shut off my 4 channel amp since I have both signal wires in parallel to each amp.

I was almost convinced I needed a new amp but then I realised what happened lol

btw when I measured the signal wire I was getting around 0.34V when it was grounded (not my official grounding spot just random metal connected to it)

I think that may be the problem. Because I thought I saw some wire showing back behind the head unit where the remote is connected at and I think it's touching metal behind the head unit. Thank you for that, I'll have to check that tomorrow.

 

[robert420 10+ year member]

sounds like the remote wire shorting out. is the remote wire a single piece of wire? or multiple strands taped together?. also, use scotch-locks when splicing into the remote wire to reduce the risk of grounding

 

[CrossoverOre 10+ year member]

if your amp turns on when the radio is off and you have it running high level its possible the signal sense is turning the amp on from opening and closing the door. a small amount of voltage will come out of the speakers from them moving with the change in air pressure.