Odd cold weather shutdown of JBL sound system

[Greg Corcoran]

Got a head scratcher...This just started in the last few weeks.
Only when the car is cold and the weather is cold (below 40 deg and during the first 5 miles or so of driving) if I hit a pothole or cross railroad tracks a bit too fast the radio shuts off. Power antenna retracts. then one of 2 things happen:
1 - If I hit the power button and it comes right back all is normal, like nothing happened. (Other than I'm annoyed.)
2 -However if radio ignores me the first few times I hit the power button, when it finally decides to turn on the radio has lost all station presets and fader/balance settings back to some default setting. and I need to reprogram everything.

If it is above 45 degrees or the car is warmed up, regardless of how cold outside, I never have an issue...

Is this a known issue with old JBL sound systems? Is there a fix?

 

[sperold]

Not a known problem with this system.

All you can do is remove the unit from the dash and look at all the connectors and wires feeding the radio, and there are quite a few.
Then take the cover off the radio itself and touch all the connectors. I once had one where a big ribbon connector was mostly disconnected, probably from day of manufacture.

If you can, hook the power leads to your portable jump starter pack, and shake the unit while on and see if it shuts off like it does in the car.

Then you are done, unless you want to take it to a repair shop, or mail it away to places you find on the internet or in car magazine advertisements.

 

[luigisho]

Your JBL system is so old. None of mine ever made it anywhere near as long. When they broke I went aftermarket. And all of mine had at least the seperate cd player break.... the head unit lasted longer but not nearly as long as most other head units I've had in other vehicles. I actually hope it's the head unit and you don't have to chase a wiring short somewhere. Radios are pop in replacements

 

[tommyturbo]

I agree with the post above, what you are describing it is as if the power is being disconnected, specifically the 12v constant, due to the stereo defaulting to base settings. Could be that the pin / wiring for constant 12v has a bad connection due to age...maybe the harness is not as tight as it once was when new.

 

[rubydist]

My bet is you have a connector somewhere in the system (most likely under the dash) that is not making decent connections and when things are cold it contracts enough to not make power connections reliably. The symptoms you describe suggest that it is the keep alive power connection that is suspect. I would start unplugging and replugging connections to the stereo.