Radio Blues

[Gludy]

OK, it looked very simple- to fit a new radio CD player.
The old one came out the hole OK, The old one had only to wires going to the speakers (running 2 downstairs and 2 fly bridge speakers with a swirch at the helm). Looked easy.

I always thought speakers required two wires - a + and -, not so here, after many hours and a replacement radio to boot, I now have a situation were I run the right speaker from one right cable, the left from one left cable and they work! BUT they stop working when one track of the CD has played! You cannot hear the next track unless you detach the wires from the switch and reattach them!!!

All I can think off is that somehow on their route they must share some sort of common negative - how this happens I do not know.

Without taking half the boat apart I cannot see what happens to all the wires but has anyone got a clue as to what could be happeneing here?

I have now spent two weekends determined to sort this out and have now reached the one track at a time situation but the radio is OK because it is always putting out a signal, it just stays on!
It is not the radio - O know that - if someone could tell me how by just taking a single +ve lead from one of the speaker terminals on the back of the radio to just one of the four single wires for the 4 speakers, I can get sound out of the speaker - If I connect all four single wires all 4 speakers go!!! It has driven me insane this last weekend.

The funny part is that, I connect the obe +ve wire to the one speaker - works OK and I get sound- then the other saloon speaker connected with a single wire at the switch and again sound comes out OK. But when the system stops between CD tracks, I have to detach both both speakers and reattach again to get them to work.

A bottle of Scoth to the person who can answer this one!!!!


Paul

 

[stamfordian]

hi,
You mentioned that the old unit had only two speaker cables ??? left and right.Has the new unit got 4???.Was the old system through a switch on boat ie,up or down.

 

[stamfordian]

hi again,
i think i know whats going on.On the old unit your switch on the boat acted like a rear/foward switch on a 4-speaker system.therfore if you connect say the front pair of speakers on new unit exactly as old unit and turn the fader switch to foward it should work as before.alternativly do away with the switch on boat and wire cabin speakers to say rear,flybridge to front and it should work.don,t run it on one cable the unit will be damaged.hope this helps

 

[stamfordian]

hi,again!!!.
just read your discription again!!.it,s got me going.Another situation it could be is the old unit was a mono radio ie just two speaker wires.this would explain whats happening.this bieng the case youve got to rewire speakers as speaker wil be wired in series live to live minus t minus.you must have speakers wired so that each one has a positive and a negative for eash channel ,sorry to go on but thinking outloud as it were!!!

 

[Gludy]

The old unit was mono with just a 12v power lead and a pair of speaker cables. It was controlled by a simple switch at the helm - you either put it through the flybridge pair OR the saloon pair. There are two pairs of wires leaving this switch.

The new unit is stereo yes - with 4 speaker output ie 4 pairs of wires. So I originally just used the front left and right and put them through the original cable doubled up so as to get both sides of the stereo.

This produced a problem of sometimes working, sometimes not although sound was always leaving the unit.

I then replaced the radio and had the same problem.
I found out after hours that if I just took the two positive sides of the cable leaving the unit and connected them individually to the cable going to the switch, (wired no -ve sides) I could independently drive the speakers! Just with the postive wires?!!!


Then I found that with the four single wires leaving the switch that go to the speakers, if I connected just one side of the cable that came from the radio, that speaker would produce the sound! In other words, just the postivefrom the unit would independently produce sound if connected to any of the saloon of fly brdidge speakers. That is just the one lead to one lead makes the speaker work!! All four leads connected make 4 speakers work.

This seeemd ok - all I had to do was wire up the four by doubling up so that I was feeding two from the left speaker in saloon and flybridge to one postive lead from the radion and the uper and lower right speakers from the other +ve lead.
So to recap - 2 postive leads for the left and right channels leave the radio and are connected to the cabele that goes to the switch. Just short of the switch I have two wires bringing these 2 postive sides in for left and right channels. I can cnnect any of the four individual wires going to the speakers to either of this +ve pair and I get sound out of the speaker.

I wired it up and bingo - it allworked UNTIL that track on the CD ended!!! The unit went onto the next track and was producing the signal but no sound!!! Then if I discoonect one of the postive lead feeding say the left spaekers FlyBridge/Saloon from the unit, and reconnect, still no sound. The same for the other postive lead feeding the right speakers BUT if I disconnect both and then reconnect, the sound flows again until that track finishes!!!! The radio just stays on OK.

I am used to wiring up high fi etc but this has me baffled.




Paul

 

[stamfordian]

hi,
I thhink the two pairs of cables that leave the switch,one to do cabin one to do flybridge feed both speakers,therfore if you wire say the left output front +and_to one of the pairs the left channel will feed 2speakers as they must be linked together.there fore you will not get stereo on say the flybridge,if you then wired the right front uotput to the other pair ie cabin you would get stereo ,aallbe it wide apart.to do job right you will have to run an extra pair of cables to both sets of speakers

 

[Gludy]

Originally I wired the left postive and right postive together as they leave the unit - then the left and right -ves as they leave the unit - this would result in one pair to connect to the cable that is going to the switch which is just one pair. When these were connected like this to say the saloon pair, I got no sound!

I am going to try and get dowm one evening this week to carry out my experiments even further. and will post results.

Thanks for your help.



Paul

 

[Guest]

Gludy, my 388 had the same switch for up/ down when I fitted cd player, just bypassed the switch and used the left/ right in normal way, and used the fader setting for theup/down, works very well on my Kenwood.

Paul.js

 

[Gludy]

pauljs_eng - on your 388 did you just have the one lead from the radio to the switch? The switch itslef just has four wires leaving it. One pair for flybridge and one for saloon. How did you wire these to the pair leaving the radio unit?

Mine only seems to work when I wire +vs only to any of the four wires leaving the switch - each of the four wires feeds an individual speaker and I get sound with just one +ve lead to it. How it forms a circuit this way is bafffling me. The unit itself is not earthed but somehow, there seems to be a common -ve that is just there without any from the unit.




Paul

 

[iangrant]

Sounds like the old system coild have been running in series - (daisy chained) but who could know. First things first - TAKE OUT the new CD player and sort out a pair of wires for each speaker first, (light bulb and battery or a 5 quid ohm meter), Otherwise it won't be long before the output stages don't just shutdown for under/over impedances they will go POP.

Good luck

Ian

 

[Seafort]

Hi Gludy,
It looks like you are just going to have to bite the bullet and rewire the whole thing, missing out the switch. As you say the old unit was mono (with only a +ve feed (a chasis earth here)) and you can get each speaker to work using just a +ve speaker wire from the new unit, the switch is probably wired with 2 wires off of each tag (you don't say), 2 going to the cabin and 2 to the cockpit. I would guess that each wire goes to a speaker +ve terminal with the -ve terminals of each pair joined together and connected to earth somewhere (possibly at the batteries).

The bottom line is that you can't use the speakers, as they are wired, with the new unit. For the sake of any new owners (or yourself if another upgrde req') wire the speakers up to all channels,, you can then switch between fwd and rear or have both and vary the the volume of each whilst still getting a proper stereo sound (you really dont want to split L+R channels to different locations). Unless the wires are laced together (read tye-wrapped) use the old ones to pull the new ones through.

p.s. You didn't mention the name of the CD. I have some on which tracks start on just the left or right channel.

Ohh.... If you do rewire remember to check the impedance of the existing speakers match your new unit.

Best of luck

DF

 

[desG]

None of the responses so far address the reason why the sound should cut out after 1 track of CD. Two possibilities for cutting out are an output overload safety circuit is operating or the internal CD digital control circuitry is being upset somehow.

The overload circuit could operate if the speaker impedance is too low, specially having two speakers switched in parallel i.e. downstairs and fly bridge. However you would expect that too cut out on the radio as well unless you play the CDs louder – even then doesn’t explain why it only cuts out after 1 track. So maybe the CD control circuits are being upset by some external feedback e.g. from external earth loops caused by the speaker wiring. Your speakers must have a ground returns somewhere. I would find these for each speaker and remove these at the speaker end so that you no longer get sound by just connecting to the +ve output of the unit. Then wire it with twisted pair cable from the +ve and –ve output connections on the unit.

In case it is just a faulty unit, try first of all connecting a pair of portable speakers temporary with a short length of cable.

Des

 

[Guest]

Don,t think it,s mono as my mates 385 has std panasonic stereo, be carefull, his works on f/b and saloon ok, take it all out and start again.

Paul js.

 

[Gludy]

I did connect a speaker to the radio just using a pair of (=ve & -ve) wires just a foot long and it worked fine. Like this it would not work with just the +ve, it needed the circuit - I found that reassuring for if I could have not made it work normally like this, I think I would have ended it all the dark depths of the marina - or maybe chucked it overbaord instead.
Seems to me like I have to work out the wire run and strip everything away and just do a plain re-wire!

Paul

 

[desG]

Did you test the CD player as well as radio with the test speaker? If that was Ok. I guess rewiring the speakers should be the answer, don't make any ground returns except at the radio/cd unit.

Des

 

[Gludy]

Yep - I just want plain simple circuits back to the cd/radio unit.
Nope, I did not test the CD after one track with the simple wiring - at that stage I did not know about the problem. I carried out my little test with 12 inches of wire just to maintain my sanity in the early stages - it was so nice to observe simple logic working!
Kind regards

Paul

 

[desG]

I would repeat the simple test to check the CD playing in case there is an internal fault with the unit.

Good luck

Des