got caught in rain - stereo now on the fritz

[jhiestand]

A little over a week ago we got caught in some decent rain and a day or so after once I got boat cleaned/dryed out, I decided to try the stereo. It initially seemed okay but it "thumped" when the amps powered up and with no music there was a decent amount of feedback/line noise. None of the noise was present prior to our rain experience.

The boat system consists of a sub amp, a 4 channel boat speaker amp, a Clarion EQ that has 6 outs (front boat, rear boat, and sub), and finally an RVC automatic volume control that feeds signal to the input of the EQ.

I started looking looking more closely at everything and noticed that the 4 channel boat amp had its red "protect" light on. Argh. So, what I've tried thus far:

1. Unhooked the 4 boat speakers and two sets of input rca's from the 4 channel amp and powered it back up. The amp red protect light didn't turn on, so the amp doesn't seem to have an internal fault
2. I took resistance readings on all 4 boat speakers and all were in the 3.6ish range. i don't know if this has any bearing or not, but I thought I could at least conclude they're not putting any sort of crazy strain on the amp and probably haven't shorted
3. Plugging the front/rear rca's by themselves back into the amp (still hooked up to the EQ) and turning it on -- RED. grrr. This leads me to believe it's the EQ or the RVC providing a bad input signal to the amp, or the RCAs themselves have gone bad.
4. I eliminated the RVC to EQ connection and just plugged ONE channel/set of rca's into the EQ, then turned back on. RED. Tried the other set of RCA's that go to the rear channel (RED), plus went to the store and bought a new RCA patch cable and tried it by itself to the EQ. All instances RED on the amp when it powered up. Note the sub amp also gets its signal from the EQ and it's been happy as a clam this whole time.
5. I bypass the EQ entirely and just run the brand new rca cable from the RVC to one channel of the amp -- it still starts up red. Same thing when I run it to the other amp channel. I'm thinking this amp isn't able to accommodate any sort of input at this point, at least not from my EQ or RVC?
6. Since the bass amp doesn't seem to have any issues getting its signal from the EQ, I take its signal RCA and plug it into one of the channels of the 4 channel amp. Start it up and Green/no red. I'm not sure if this is a valid test, but I'm the 4 channel amp is apparently able to handle at least SOME input signal?
7. I then hook my mini-jack to rca cable directly into one of the 4 channel amp inputs, connect it to my ipod and fire it up. It starts up and shows green, plus I can turn the ipod up and get clean music. Same when I connect it to the rear input of the amp. Another indicator the amp can handle at least a little signal.

So I'm stumped on what to try next. The 4 channel amp is up under the gunnel and there's very little chance it was directly exposed to any water. The EQ and RVC are up under the dash, but they MAY have gotten some exposure. All the boat speakers still have the 'pantyhose' covering them, but the one by the driver is angled up and may have gotten wet. From tests #2 and 3 I doubt it's the speakers.

I don't think I can rule out a problem with the front/rear output channels on the EQ. Its sub output channel operates fine. I also can't rule out the RVC due to #5 above. Both had a higher chance of being exposed to water than the amp. However, the amp seems to be the common denominator so I'm highly suspect about it.

Anyone have any thoughts or offer any advice on what to try next? My troubleshooting skills are not exactly legendary when it comes to this stereo stuff, so any advice would be greatly appreciated!

[Chexi]

Consider that it might be your head unit (specifically your outs for your mains). Is your head unit a marine unit or a car unit? Since the sub works even on the other channels of the amps, it seems like you should be able to eliminate the amp from your list of suspects. That (I think) leaves only your eq and your head unit. Take the eq out of the equation by running your head unit directly to the amp. If you still have your problem, it's the head unit. If not, it's the eq.

[jhiestand]

My head unit is a Clarion XMD3 (marine) and IS exposed to the elements, altho supposedly is relatively water resistant. It's not on my list of suspect components because I don't really use it for any signal (we don't use the radio). Pretty much its only purpose is to power up all my components and act as the only clock on the boat.

But.. you do make a decent point. It does have a couple channels of RCA outs and that's the one source I have not tried to feed into the amp. I could connect the head unit directly to the amp to see if that worked okay. If it did, that would make the RVC and EQ suspect.