fuse size or a short, boat

Good day,

I inherited a boat with a Kenwood KDC s2009 CD/AM/FM radio. 

BACKGROUND

Everything else regarding electronics works fine on the boat (gauges, GPS, etc.).  Just got around to looking at the radio wiring and discovered a blown fuse inline from the back of the HU to the terminal block behind the dash.  The HU has a larger gauge red wire that houses a smaller gauge red and a yellow wire.  That smaller gauge red wire has an inline (cylinder fuse) 250V 3amp.  So I replaced the fuse with same, heard the CD motor in the unit spinning, it ejected a CD (nothing good btw) and then there were no lights on the HU display.  So fine, I press PWR on the unit, the display comes on, I here static and a station for a few seconds, then the fuse blows again.  So I put another fuse in, same behavior.  Key is not in ignition during this evolution.

So here are my questions, does a 3 amp fuse sound appropriate for a kenwood car stereo that says 4 x35w (in other words, did previous owner just use the wrong fuse)?  If it is a short, would it not trip immediately (why wait a few seconds?).  I am a newbie when it comes to car stereos, so any expertise on how to appropriately troubleshoot would be wonderful.

Thank you

slightly clueless, but learning

I would say that no, a 3A is not adequate, this is why the delay between turning on, and blowing. Try a 10A, or if necessary, a 15A, but try the 10 first. Voltage rating won't be quite so important, but be certain it is at least 12V... (they all will be, though, so just remember that the current rating is the goal of your quest, here, and don't worry about the voltage so much.) This will likely solve your issues.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

If the fuse is on the main power wire, it is supposed to be 10 amps.Support the12volt.com

smelkin wrote: Have since used a flashlight and see that red wire (one with the fuse here) has 1amp printed on the wire...so back to the drawing board.  Don't think I want a 10amp fuse inline with a 1amp wire.

You're right about that. You said it was a red wire... Is there a YELLOW wire as well? The red wire is usually the ignition or accessory wire, the larger yellow one will be the main power wire.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

Yes, my apologies, there is also a yellow wire coming out of the HU, seems to have a square fuse assembly there.slightly clueless, but learning

Ah... The yellow wire is the wire with all the power for the deck. It traditioanlly goes to a "constant" or "battery" lead, not through the ignition switch. IT should have the 10 to 15A fuse in it, and the red wire will be perfectly safe with a 1A fuse in it. If you are continuing to blow this particular fuse, then my guess is that there is something wrong with the deck. I've never seen an accessory lead have anything bigger in it than a 3A.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."