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View Full Version : Two things: Are they related?


TonyB
05-22-2006, 09:55 AM
My three month old Pioneer head unit quit putting out sound. It is a non-marinized DEH-P4700MP. It had been working perfectly until this weekend. When I powered it up, all the functions were operational except there was no sound. I did not check the voltage to the speakers but I suspect that the internal amp IC got fried.

Later that day, when I got home and the boat was on the trailer, I turned on the key (but did not crank the boat) and powered up the head unit again to see if I could figure out what was going on. While I was messing with some of the function buttons my tachometer pegged (maxed) and stayed there until I turned off the key. I tried once more to power up the head unit and see what was going on, only this time the I could not get it to come on but after a few moments the tach again maxed out.

How might the Pioneer headunit issues be related to the tachometer issues?

Could I have caused any other problems while tinkering with the stereo?

Thanks.

TonyB
05-23-2006, 09:21 AM
{chirp chirp}

ajgressette
05-23-2006, 09:49 AM
Unhook the positive wire from your amp and radio. Most radios also 2 hot wires. One is constant power and the other is switched via the key. See if this corrects the problem with the tach. If so I would suspect that you had two speaker wires short and this fried the internal amp. Voltage could be back feeding into the system screwing up the tach.

I would also make sure all the wires attached to the key switch are making good contact as well as all the switches in the dash.

Check your battery connections and make sure your getting voltage to the starter.

If this does not work try a hammer. :D

TonyB
05-24-2006, 12:27 PM
Unhook the positive wire from your amp and radio. Most radios also 2 hot wires. One is constant power and the other is switched via the key. See if this corrects the problem with the tach. If so I would suspect that you had two speaker wires short and this fried the internal amp. Voltage could be back feeding into the system screwing up the tach.

I would also make sure all the wires attached to the key switch are making good contact as well as all the switches in the dash.

Check your battery connections and make sure your getting voltage to the starter.

If this does not work try a hammer. :D


I've pulled the Pioneer headunit completly from the dash (disconnected wiring harness) and everything is back to normal (except there's a hole in my dash and I don't got tunes).

What's odd is that I ran a non-marinized Alpine Headunit in my boat for years without any problems. But I have the Pioneer HU for no more than 3 months and it checks out? That's not right.

Rockman
05-24-2006, 01:56 PM
Check all your grounds first. That is usually 99% of the problem.

Then if they are ok, check any fuses you may have leading to the Stereo.

Lastly, there may be one fuse inside the actual unit as well to check.

Something seems to be shorted as you say the Tach had jumped up. Some non-grounded current is running through your wires.

JimN
05-24-2006, 02:22 PM
Put one lead from your meter on the head unit case and the other on the battery - terminal. Set the meter to voltage and see what it reads. If it's more than about .01Vdc, you have no ground, or the ground is very bad. Next, set the meter to ohms and read it. It's probably very high resistance. The dash ground isn't great for anything other than lights, etc. I would recommend running a heavier wire (8ga) to the dash and abandoning the factory ground wire. There's usually one point where everything under the dash connects to ground and you need to replace that with a terminal strip or distribution block.

pilot02
05-24-2006, 02:37 PM
FYI - I bought a Kenwood "Marine" CD deck 5 years ago. It checked out after a year. Luckily, I had a "replacement warranty" on it. In the process of dealing with it though, I found out the ONLY difference between my "Marine" deck and the automotive was the white face plate. NO differences at all in the internal construction.

Some manufacturer's do make marine units which truly are built for the environment but you need to research the subject before buying.

TonyB
05-25-2006, 10:04 AM
Thanks guys.

Pilot02, knowing, as you do, that the difference between many marinized and non-marinized head units is purely cosmetic and based on the success I had with my previous hu, I figured I might as well go with non-marinized system. Plus you tend to get more features for less $$ in standard application stereo HUs. And .....seeing as how I had a $150 gift certificate to "Best Buy" I might as well look there first. That is what led to the purchase of the Pioneer DEH-P4700MP.

However, the warranty on my Pioneer is useless as it was not designed for a marine environment.

If for no other reason than warranty application, my next stereo headunit will be defined as "marine".

Thanks.

JimN
05-25-2006, 10:11 AM
How would they know you had it in a marine envirnment?

TonyB
05-25-2006, 10:15 AM
How would they know you had it in a marine envirnment?

I think I will see if I can get my money back. ;)