Hey--

I've got this weird problem happening with the radio in my car, and I'm not sure what exactly is going. Basically, it goes like this. I installed a radio in my car back in April, and probably drove 500 miles with it this spring, worked great. Fast forward to May, due to a fluid puddle on the floor I decided not to drive it until I had time to look at it. Finally, about 2 weeks ago I had time to look at it, battery completely dead (been sitting 4 to 6 weeks). Charge it up, car starts fine, no issues at all, but I notice my radio was turning on and then turning itself off (retrosound unit). Yesterday I took it out again, started up fine (been sitting for two weeks) and the radio would play for like 30 seconds, then reboot, then play for 5 seconds, then turn off for a minute, then come back on for a little bit, etc.

My battery is a 4 year old Optima red top. My question is:

a) is this a battery problem?
b) is this an alternator problem?
c) is this a radio problem?

Because I'm not exactly sure. I know that the C6's flake out when the battery gets old, wasn't sure if my radio (since it's based upon new technology) wasn't getting fed bad voltage or something. Was hoping that someone else had a similar experience sometime and could lend some insight. Thanks! About the only thing I could think of to do would be to measure the voltage at the battery, see what it's putting out.

 

Recheck the radio connections, did they get wet, or the radio itself, from whatever caused the puddle?

 

Could be a short in the switched power wire somewhere. Does the radio maintain it's setting when car is off?

If wiring looks good, it could be the radio.

 

No, the puddle (transmission fluid) was totally unrelated.

 

It does maintain its settings when the car is off. I'm going to test the voltage and see if it's low or something, perhaps my voltage is getting too low below 12 volts and is causing the radio to drop out.

 

Ack, I checked the battery today and it's 12 volts, and when I put it into the aux position I can see the backlight of the radio kick on but it doesn't start. So I'm about 95% sure it's the radio, as it's obvious that it's getting power.

 

What year is your C3?

 

Had a problem like this that kept getting worse and worse until my car wouldn't start and I got a new battery. Never had the problem since. Also my gen light is always on so I think there might be something messed up besides the battery with my car, but thats another story.

 

This happened to me yesterday while testing my connections. Radio went on then off; antenna went up and down. Battery is new, car was not started. I'm fearing it is in the ignition switch but I hope not

 

Check your fuse.
Had the same mystery issue with an aftermarket stereo.
Worked, stopped, worked, stopped. No apparent reason.
Troubleshooting eventually produced a bad inline fuse. Cheap fuse cap had come loose from the filament. Sometimes it made contact and others it did not depending mostly on how hot or cold the filament got. Got lucky when troubleshooting and simply wiggled the hot wire with the inline fuse and viola the radio started working.

 

My car is a 72 for the one poster that asked. I thought about the fuse, but that's almost impossible since the LCD backlight turns on, right? It kind of depends on how the deck consumes power, since it's fed both a 12v power and the accessory power. If the accessory power powers the LCD backlight but the 12v powers everything else, then it would be possible for there to be a bad fuse or holder. I'm not sure how those things interact (12v and accessory) normally, first radio I'd installed in like 20 years.

 

You can't assume the battery is "good" just because you measured 12 vdc before you fired anything up. A good battery will stay near 12 volts when the engine is started. The starting voltage with a bad battery might be quite a bit less.

If the battery isn't "working", measuring its voltage rarely tells you anything (unless complete cells are dead).

 

Hmmm, interesting, I did not know that. Perhaps I should try a different battery to see...unfortunately, I don't think I've got one in my other vehicles that will fit because they don't have the screw in type terminals available. I do know that in the past when I've had bad batteries, the voltage was off from 12 volts (9 to 11), I did not realize that wasn't always the case.

Is there any way I could measure anything while in the accessory position (amps maybe)? The voltage drops about .1 when I'm in that position and trying to run the radio. I would think that there would be something I could measure, since in that position the radio is basically the only thing going.

 

I believe your battery is fine. Car is starting up and running. The only way to catch this gremlin (you and I) is to have a voltmeter on the switched B+ when in the acc. position. When the stereo drops out the meter should catch the voltage loss. If not it may be in the stereo. I'm leaning towards the ign circuit on mine.

 

Ok, so I did some testing tonight. First thing I did was replace the red top battery--it was 4 1/2 years old, and it has a reputation for causing flaky electronics behavior. Replaced it, and now the radio works in accessory mode, which is a big improvement, so the battery was definitely part of it.

However, it's still flaky when driving. I have determined though that accelerating hard will make the radio flake...which means that it's probably the alternator that's the issue. Probably a logical guess? The volts when driving are 13.5, accelerating though does not seem to increase the voltage. I can't think of any other reason the radio would die when accelerating other than the alternator.

 

Bad connection somewhere or its the radio. Check the fuse but also double check the fuse holder and clean the holder where it connects to the fuse. I had an intermittent brake light problem one time and I kept checking the fuse with a test light which always showed good. It was the pressure I was putting on the end of the fuse with the test light that was causing it to make good contact. Once I cleaned the fuse holder, I solved my problem.

I am assuming you are using the factory wiring and the fuse in the fuse box. If you wired out an inline fuse for the radio, double check that fuse holder and double check where the wire is tapped into for power. If it's tapped into the fuse box, check that connection.

Some people have had problems with how the fuse box connects to the wiring harness. There is a bolt that holds the the two together in the engine compartment. It could be loose. Or the connections inside could be corroded or loose and requiring attention. Do not pull the harness apart from the fuse block without first disconnecting the battery.

DC

 

Well, ironically, right now as I was searching for 'alternator radio' I ran across a post from another c3 owner who also had a retrosound radio that was doing exactly the same thing (dying when accelerating). I just have to prove the voltage going into it is good, and I should be good to go to get a radio replacement.