Kenwood and Boats don’t mix?

I installed a Kenwood KDC-3022 head unit and some marine speakers into my boat the other day. We went out and had a blast. The music sounded great, bass response was phenomenal, all that stuff.

Well two days later I went to work on the boat and couldn't get the Kenwood to power on. So I charged the battery and then hooked the CD player back up...nothing. A couple of hours later I hooked it up again and it WORKED!

Get this, now it won't work again. Checked all the fuses and wiring, it's good. I even tried to hook the unit directly to the battery (common in marine installs) to check and I noticed something interesting. When the wiring harness is plugged into the back of the Kenwood, a spark shoots out between the battery and the boats main battery cable when I go to hook it up. But when the harness is unplugged from the Kenwood, there are no sparks.

I called Kenwood Tech Support and I don't think the guy even knew what a boat was, let alone how to help with this. I'm thinking some water may have gotten into the unit and caused a short and that's why there's sparks firing when the harness is plugged in.

Please let me know if you have any ideas, I'm about to go crazy trying to figure this out.

"When the wiring harness is plugged into the back of the Kenwood, a spark shoots out between the battery and the boats main battery cable when I go to hook it up."
please explain in more detail. what part of the battery is arcing?



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Prove your connections, use a meter!
I promise, I'll behave!

The deep cycle battery I have has the two main posts and two threaded posts w/ wing nuts. I use the threaded posts with heavy duty ring terminals to go from the battery to the distribution panel. So when I go to connect that wire, the lead base portion of the threaded studs shoots a blue spark. I tested this some more and disconnected and reconnected both the hot and the ground and the ground created a much bigger spark at the battery post.

bad connections will cause arcing. i would remove both positive and negative cables and clean the ring terminals as well as clean the posts. then i would apply an electrically conductive grease to the posts and terminals. that should eliminate the arcing problem, and allow you to troubleshoot the radio problem from there.

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Prove your connections, use a meter!
I promise, I'll behave!

Could a short inside the stereo due to water also cause the sparking? I have plenty of other electronics and none of them cause a spark. Thanks for your help by the way.

a short inside the radio should blow its fuse!

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Prove your connections, use a meter!
I promise, I'll behave!

Tried it all and still getting nothing. It's killing me though that it worked perfectly for hours and hours the other day and even for a short while earlier today and now it won't even power on.

Oh well, Clarion makes a pretty decent MARINE head unit that might be worth the investment.

Couldnt you use a normal HU and just make something to go around the headunit so that it gets air, but keeps water out?

is the battery charged? and by what method do you charge it? also have you measured the voltage at the harness while plugged into the radio and with the radio on?

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Prove your connections, use a meter!
I promise, I'll behave!

this Kenwood is an automotive HU and it's protected by a plastic splashguard. I know that marine units have a lot more moisture protection and are splash proof even without a splashguard.

the battery is fully charged (12.7V) and I've been using a brand new multistage portable 15A charger.

the one thing that's really confusing me about what was said earlier about the bad connections is that none of the other electronics on the boat cause a spark. I changed the fuse too so that's definitely not it.

one thing I may have left out, this unit was given to me for free by a customer and he claimed that it wouldn't turn on as well. I just figured he had the wiring wrong since it worked perfectly for me, so maybe I just got lucky for a little while but it's a dud....who knows...

Have you opened up the unit to take a look at the board?

i dont mean to sound like i'm beating a dead horse but you said the battery measured 12.7 volts. is that underload? here's what i'm getting at. measuring battery voltage underload will tell you that the battery is good. so now you need to measure voltage at the harness and prove that it see's voltage. now connect the harness to the radio and attempt to turn it on and measure for voltage again. if you read 12.7 volts on your dmm your radio does not have a short but has a problem, perhaps a bad connection. if you measure significantly less than 12.7 volts again your radio is a dud.


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Prove your connections, use a meter!
I promise, I'll behave!

I opened it up to see if I saw anything obvious but ended up not going much further than 5 screws deep.

That's a very good point about the battery and measuring the voltage. I'll be sure to do that tomorrow and I'll keep ya'll updated.

In a moment of shear impulse (and thanks to a very good associate discount) I bought a brand new Clarion Marine HU and just installed it...works PERFECTLY!

One thing I did notice, the first time I hooked it up directly to the battery to make sure there was no voltage issue and it turned on fine. Once installed, there was a 10A inline fuse that I had put in when I installed the Kenwood and a 15A inline fuse that came on the lead from the wiring included with the Clarion. The 10A fuse (a slow blow even) blew immediately, so I got rid of it altogether and it's working great, no blown 15A fuses or anything.

So this all leads me to conclude that battery voltage, bad connections, etc. were not to blame. It was the Kenwood the whole time. Oh well, the Clarion sounds even better.

Thanks for all of your help!!