In May I installed an Alpine CDA-105 car stereo to replace the '93 stock chrysler p.o.s. it was sufficient and had all the options I desired. After some weeks, as the summer heated up, it would go non responsive, although the display still worked. It wouldn't function until the next day starting the truck in the morning. Thought it was the stereo. Swapped it out with a new stereo same model, weeks later as the weather was hotter than normal (september by now) it started happening again. I have swapped the stereo out for a third time, suspicious that it was something else besides the stereo. I have checked all the harnesses and connections to be tight. It always acts up after the truck has run and is at it's hottest after shutting off the truck and restarting it.

I am thinking that the rectifier and voltage regulator contained inside (part of) the alternator may be puting off some AC waveforms or something that the digital stereo doesn't like, but only when the temperature is very warm. There is nothing else digital on the truck to be affected by this. Perhaps the capacitors in the rectifier are acting out at high temps and not alowing the digital DC supply to the stereo? I've checked the voltage while running at between 13.5 volts and 14 volts, there is a new sealed battery of hevy duty type which is in sound shape.

The only other noticeable electrical mystery with the truck is that the headlights will dim very slightly for some tens of seconds and then re brighten as the truck is first started from cold. This can only be noticed when it is dark. This does not seemed to be related to the stereo in any way or to any cycling of the A/C compressor, or anything else. BUT, it does seem like some kind of voltage problem maybe with the regulator.

Is there some way to test the alternator (rectifier and regulator inside it) without an occiloscope?

Any other ideas? I'm all wired up over this.

 

I have all alpine digital electronics in my truck and have never had a problem ever.The only issue i did have is when cold in the morning and the grid heaters come on my stereo used to cut out,which i new it was from the power draw off the grids but i corrected the problem by grounding my amps directly to the battery and no more worrys.

 

first get a pair of side cutters and just cut everything out. second cut a hole in your bed and slap a stack on the old girl and third listen to the sweet, sweet music of the cummins band

 

Sounds like the stereo is getting hot and shutting down on you. They get pretty hot behind the dash and will do that.

As for the lights dimming on cold starts, that's normal grid heater cycling causing a good draw on the electrical system. Nothing to worry about.

Like Fast59, I've had the grids draw the voltage down enough to make the stereo cut out. I just leave the stereo off until the grids quit cycling.