CD/Radio Switching On/Off During and after Start

[Qavion]

My CD Player/Radio recently started playing up. It's only about a year old. When I turn on the ignition, the display switches on/off repeatedly every second or so (as if power is being removed and restored). It continues to flash for up to about 30 seconds (if I'm lucky), then it will be fine for the rest of my trip! However, a few times it has died completely, during start (each time blowing the fuse).

When I insert a new fuse (ignition off), there is some arcing from the fuse to the fuse holder... so something else is in the circuit. The circuit diagram shows the engine immobiliser off the same fuse, but I've had numerous aftermarket immobilisers fitted, so I don't know if it still is in the same circuit.

Is it likely that the immobiliser is causing the problem (if it is in the circuit), or is it more likely to be the CD Player/Radio? I've replaced the relay for the CD/Radio, the fuse hasn't blown for a while, but the display continues to flash.

Thanks.

Cheers.

Ian.

[ozontour]

Sounds to me like your cd player is not getting enough power to the unit.

try isolating it from any other electrical components, ( immobiliser), then run the cd off the battery direct to check it.

I suspect though your head unit has had the richard...

Justin

[fflyingdog]

Are you sure you have not got a bad earth or live? Loose connection will manifest as pretty much you have explained.

Nick S4s

[Qavion]

If it was a loose connection, Nick, I would have expected the CD/Radio to continue flashing, though, for the rest of the trip... It runs perfectly afterwards. Also, I can't see how a loose connection would cause a fuse to blow. I'll pull it out anyway, today, and check the rear connections.

Sounds to me like your cd player is not getting enough power to the unit.

Possibly, Justin... then after the alternator kicks in, and the voltage rises, it's ok. Anyway, as you suggest, I'll try isolating it or running the cd off the battery direct to check it. I think the immobiliser has it's own fuse, so I can try removing that: Even though I might not be able to start the car, I might be able to get the CD/Radio to run on Accy(?).

I suspect though your head unit has had the richard...

I'm hoping it's something simple like that, but... Anyway, thanks for the suggestions.

Cheers.

Ian

Update:

Seems the blowing fuse and the flashing CD/Radio display are two separate issues.

I had trouble finding an applicable wiring diagram. The paper Service Manual I got from my local Lotus dealer didn't seem to match my car.. and the online one, didn't seem to match, either. I assumed it was a combination of both....

In one of the diagrams, I noticed that the ALDL connector came off the same fuse as the CD-Radio.... I normally leave my Freescan adaptor (circuit board) plugged in (not sure if that's bad or not?). It was sitting on top of the CD/Radio amplifier in the passenger footwell. As soon as I touched the adaptor, there was a flash of light and sounds of arcing... Part of the adaptor circuit board shorted to the metal case of the amplifier! (feel kinda silly putting it there in the first place without insulating the circuit board ). Hope it hasn't damaged the car's engine management system.

After disconnecting the ALDL adaptor, I replaced the radio fuse which had blown again (after the flash). However, the CD/Radio display continues to flash on start up.

I tried removing the fuse for the antenna motor, to see if that was dragging the voltage down, but no luck. I also pulled a fuse from the engine immobiliser, but that had no effect either (not sure if that is even part of the circuit).

So... back to the drawing board...

Cheers.

Ian

Edited June 15, 2008 by Qavion

[ozontour]

Hmmm...Maybe try googling the cd player model number or going to the manufacturers website and looking at the FAQ's sometimes they have a technical support email that can assist with common issues and errors. Usually though, from working for many years in the ICE industry, it is either not recieving enough current, (either not good earth or not good power), or a fried unit.

also if you are sharing your head unit wiring with the amplifier, maybe the amp is either stealing your power and you need to install thicker gauge wiring or your amp may even be starving from not enough earth or power.

Try doubling up the wiring to the amp if this is the case. If it fixes it then run thicker wire.

Goodluck

Justin

[Qavion]

Haven't got around to trying your latest suggestions, but...

Disconnecting the amplifier allows the head unit to power up normally.

When the amplifier is connected, there is a relay in the amplifier clicking on and off on start up. I found some circuit diagrams on the internet for the amplifier and the only relay in the amp seems to be the muting relay (I thought about buying a new amp, but there is nothing on the market as slim as mine... only 1&3/16".... Size matters when the amp is mounted on the underside of the glovebox).

My transitor theory is a little rusty, but should the mute control line need power (+ve) to have the amp operate normally?

I'm not really sure if the relay contacts are shown in their normally relaxed (no power) state.

Thanks for any suggestions

Cheers.

Ian

Edited June 24, 2008 by Qavion

[fjmuurling]

Hello Ian,

the relay contact shown is in it's no power state and yes the mute cont. line needs power (+ve) to have the amp. operate. Reading from your diagram the relay contact is in series with the power line. Is the mute cont. line connected to your Head Unit ? It looks like you got a bad signal coming on the mute cont. line. Try searching in that direction ie check the voltage on the mute cont. line.

Hope this helps

Freek

[Qavion]

Try searching in that direction ie check the voltage on the mute cont. line.

Thanks for the tips, Freek I'll look into that when I get back from my holidays in a few days time.

I also assumed that the mute signal was coming from the head unit. What makes this problem difficult to diagnose is the fact that the relay pulses regularly for a while.... then operates normally. I'm not sure what kind of fault in a component would cause this. At least the circuit is easy to work on. The components are super large. I might try changing a few. BTW, what would happen, say, if capacitor C504 was breaking down?

BTW, I took the car to the same people who installed the new head unit a few years ago and they seemed to think it was the amp, because when the amp was taken out of the circuit, the head unit display stopped flashing. I asked them to send it to the local Sony repair shop. Unfortunately, the amp is so old, Sony no longer service it.

[ozontour]

Hi Ian

the p/cont wire is used as a trigger wire to power the amp from the head unit and will only turn the amp on when the head unit is powered.

it will be connected to the accessories or cont terminal on the amp

you will have a constant power supply to the amp also.

if the power wire and the earth wire are not heavy enough, (usually the earth), then your head unit will suffer.

I would try a heavy earth on the amp and head unit as well as a heavy power supply to the amp.

I rekon it is easier to try the easy stuf before paying for repairs to an old amp...theat may not need it...

goodluck, Justin

[Qavion]

also if you are sharing your head unit wiring with the amplifier, maybe the amp is either stealing your power and you need to install thicker gauge wiring or your amp may even be starving from not enough earth or power.

Try doubling up the wiring to the amp if this is the case. If it fixes it then run thicker wire.

Hi, Justin

I checked the wiring today. All the earth wires and power wires to/from the amplifier are doubled up and run into rather large looking single earth and power wires. I checked all the connections, re-doing some and shortened some wire runs, but the CD Player/Radio display & Amp are still doing the same thing.

The mute voltage was about 10.7 volts with the amp disconnected (don't know if that is normal or not). The amp and player combined seem to pull a constant 0.5 amps even during the flashing period.

Might have to take it to someone with a test rig where I can check the amp voltages at various points.

Cheers.

Ian

[lotuseffect]

Hi Ian,

I had exactly the same problem (flashing display etc) when I upgraded the tape player in my 71 spitfire to a cd player. Not knowing what the issue was, I took it to a stereo specialist and they simply fitted a higher amp fuse and hey presto everthing worked fine! Apparently cd players suck a fair bit more power than tape/radios and mine wasn't up to it. Maybe that's what's happening with yours...especially when there is a drain on the power from elsewhere in the vehicle at the same time? Si

[Qavion]

It would be great if it was a simple fix like that... I have a 10 amp fuse in there at the moment, but the system is only drawing half an amp. I also had a 15amp fuse in there for a while, but the effect was the same.

Assuming they aren't too expensive, I might invest in a variable power supply and run some voltage checks myself.

[ozontour]

G'day Ian

might be cheaper to bin the cd player and try another?

CD players are so cheap nowadays, i bought one a while back that was a cd player as well as Mp3, but also takes a USB flash drive in the front of it. The unit cost me $139 wholesale here in Brisbane.

[Qavion]

might be cheaper to bin the cd player and try another?

Indeed it might... I saw a replacement head unit for only $118... bought it... and it worked!!!!

Everything works perfectly now : )))))

Now I feel kinda guilty for doubting you I just don't understand why it worked. Perhaps a faulty power supply output (for the mute circuit)?

Anyway, thanks to all for your support. You saved me a lot of heartache

Cheers.

Ian

[ozontour]

No Worries Mate!

Glad is all sorted out for you.

Justin

[Qavion]

Everything works perfectly now : )))))

lol.. spoke too soon. Now my antenna doesn't go up when I turn on the radio. Just wondering what signals the antenna to go up. I'll check the fuse, but is there a connection which hooks into the CD/radio somewhere (which may have come adrift)?

Thanks.

Ian.

[matk]

There's normally a cable off the CD player that you have to hook into the power circuit for the aerial, as a trigger for the aerial. Did you get a manual with your new player? If the player wiring has standard ISO connectors and colouring the wire should be blue. It's not normally part of the ISO connector block, so it's very conceivable that you've wired the stereo up without it, it needs separate connection.

[ozontour]

Gday Ian

Mat is right, there should be a blue wire on the loom, the one that is labelled P.Cont usually...

this is the same one that you send to the accessories side of the amp, which powers it when you switch the cd player on. just run a second wire split from that one and there should not be an issue...sometimes however, they code things differently, but should be on the install diagram which is the pcont/ ariel/amp wire.

Goodluck!

Justin

[Qavion]

Thanks guys, that's what it was.

The blue (maybe purple) wire was the shortest in the car's loom. As soon as I pulled the stereo out, the wire pulled out of it's quick disconnect socket and it fell down behind the heater controls. The antenna wire on the new CD/radio was taped tightly into the main wire bundle, so I missed it.

Now, dare I say it, all is finally working well.

Cheers!

Ian.

[ozontour]

Excellent news..Happy motoring and now you won't hear all the fibreglass creaking as you drive lol..

Justin