..takes 10 minutes or more for stereo to work. What?

[Jim Ed]

When I turn on the car stereo I can barely hear it.
Then after 10 minutes or more It plays almost normally.
It has a stereo, amp booster, and two 5 1/4 inch speakers.
Could this be due to bad speakers?
I have never heard of speakers that had to warm up first.

[Marc]

Not certain you have the same issue, but I had a power amp in my car that was very fussy about the input voltage. Already had oversize dedicated power wires and a solid ground, so that wasn't the problem, but whenever the voltage dropped down below a certain level (typically when lights & wipers were on, at idle) the amp would drop out. Sometimes it'd be just fine under those conditions, but just a little more load on the electrical system such as brakelamps or t'signals would kill it.

Slapped another amp in and haven't had the problem since.

It's possible that for that first 10 minutes after starting up your battery is drawing enough charging current to drop the supply voltage below that critical point, and after it's back up the amp kicks in.

If you're saying that you have the same symptom even when you turn the radio on with the engine off, it could mean that there's a high-resistance point somewhere in the power feed to it or the amp that "heals" a bit after it's been passing current for a while (that can happen due to heat expansion at the connection).

=> Start by ensuring you've got adequate wiring to the amp and it's well-grounded.

[Jim Ed]

I wonder if it might have something to do with the sound filter that is in-line between the fuse box and the stereo and amp. It is over 16 years old.

[Ol'fogasaurus]

Have you checked your grounds on your equipment? Take the funky woven ground strap then add to that connections, the proper gauge of wire being used and then there is length of wire vs. voltage drop.

As the VW's metal gets older so does it's ability to pass grounds and other things. Add to that any welding done, was the metal clean when it was done so forth. Chasing electronics is a very frustrating game as you are finding out.

Lee

[Jim Ed]

There is something wrong with the add-on amp. If I gently tap it with my cane, it starts working again.

[Ol'fogasaurus]

"Raising cane" with it is not a fix; tap it not so gently with a BFH then replace it. Sounds more like a problem on the board where something expands when it get warm and makes finally makes the connection you want or there might be a problem with the wiring inside. Unless it is a rare OEM unit then it would probably cost more to fix it than to replace it.

I forgot to ask, is it old enough to have tubes?

My opinion is worth less than you paid for it!

Lee

[Jim Ed]

Unread post by Ol'fogasaurus » Fri Apr 20, 2018 7:55 pm

"Raising cane" with it is not a fix; tap it not so gently with a BFH then replace it. Sounds more like a problem on the board where something expands when it get warm and makes finally makes the connection you want or there might be a problem with the wiring inside. Unless it is a rare OEM unit then it would probably cost more to fix it than to replace it.

I forgot to ask, is it old enough to have tubes?

My opinion is worth less than you paid for it!

Lee

I got it at a Radio Shack back in 1999 I think.

[Jim Ed]

When it gets warmer I plan to remove the amplifier and install a new stereo without an add-on amp. I think the new stereo has a built in amp. It probably won't need the extra clarity with the engine noise.