100 series riddle...

[DAA]

Okay, this is about as NON 4x4 as it gets, but it's been bothering me all winter and if one of the brain trust here can get me headed in the right direction I'll be very grateful.

My daily driver is a 2002 LX470.

The radio doesn't work when it's cold. It has the Mark Levinson "premium" sound package, with nav and all the goodies. I'm not sure exactly where the temperature cutoff is, but basically at anything below the low 30's ambient, when I start the rig, the radio doesn't work. The head unit functions, and all the audio functions "appear" to be working, but no sound out of the speakers until the rig is well warmed up. Most mornings, temps somewhere in the 20's or lower, driving to work, the radio makes no sound until after I've been driving 15-20 minutes. If I get it good and warmed up like that, park it, then get in and start it again soon after, the radio is still working. But if it sits long enough to get cold, it's back to square one and needs to be driven for 15 minutes before it makes any sound.

When ambient temps are in the 40's, it's generally no problem, it works right at start up.

This is new, this winter. Had no such problem last winter.

Any guesses as to where I should look?

Thanks!

- DAA

 

[spencevans]

My wife wants to know if you have you checked the radio fluid levels?

 

[StormRider]

Maybe there's an amp external to the head unit that's having issues with the cold?

 

[flexyfool]

The failure only around 30 degrees may be a clue. Electrolytic capacitors can have water vapor inside them from the factory or can have a bad seal that allows water vapor to collect inside. The water freezes. The internal surfaces separate too far apart for the capacitor to charge. The associated circuit will not work. Such a bad capacitor can be identified by the top of the cylinder being bulged out. It can actually be made to work temporarily by heating it with a butane torch/lighter. If you can get to the amplifier box, can open it, and can identify such a capacitor, then it is easy to find a replacement component and solder in a new capacitor.

 

[bryson]

Maybe there's an amp external to the head unit that's having issues with the cold?

This is my guess as well. I believe your factory amp is under the passenger seat - you could pull it out and open it up easily enough I'd guess. Maybe there's a cracked circuit board in the amp that contracts when it's cold causing a break in the circuit? When it expands as it warms up, it makes contact again. Or, I'm sure there's several people that just take it out and run an aftermarket head unit, so there should be an ample supply of used-but-working units around...

 

[DAA]

Hey thanks for the input fellas!

Gives me a direction to begin. I'll find the amp and remove it for inspection.

- DAA

 

[DaveB]

When we need to find thermal problems with the electronic circuits we design we use a heat gun and freeze mist. Warm the radio circuit boards up with a heat gun till it starts to work then freeze the components with the freeze mist till you find the parts or circuit board area that kills the radio. You can find the freeze mist at the electronic supply houses.

 

[DAA]

That's good to know. I was already thinking about the heat gun part, but hadn't a clue about the freeze mist stuff.

- DAA

 

[cruiseroutfit]

When we need to find thermal problems with the electronic circuits we design we use a heat gun and freeze mist. Warm the radio circuit boards up with a heat gun till it starts to work then freeze the components with the freeze mist till you find the parts or circuit board area that kills the radio. You can find the freeze mist at the electronic supply houses.

That is some great info

 

[frieed]

That's good to know. I was already thinking about the heat gun part, but hadn't a clue about the freeze mist stuff.

- DAA

Freeze mist,

commonly known as canned air (Dust-Off) turned upside down...