Electical cut out to stereo when car is cold or reverse

[josh72ooh2]

I've been trying to figure this one out for a while now...

I've hooked the stereo up 2 different ways and the issue occurs in both instances.

I used to have my stereo's positive hooked to a positive wire coming from the ignition switch.

My current set up:

My battery is in the trunk and there is a positive lead terminal near the driver's firewall.

I have my stereo's positive lead hooked up to that terminal.

I installed a new alternator (85 amp with internal regulator).

When the car is cold, and i hit the brakes, the stereo cuts out or shuts down for a second and then comes back on.

Sometimes, when the car is warm, and i put it in reverse, the stereo cuts out too...

I'm guessing that the current needed for the brake lights or reverse light is interrupting the stereo somehow... but why or how?

Any ideas?

Thanks!

-josh

[Tommy]

Positive side sounds ok since it didn't change but how about ground?

Tommy

[tashakes]

Easy to troubleshoot

Connect the stereo's ignition (usually red) wire together to the stereo's battery (usually yellow) wire. Hit the brakes and see if it still does it.

If it does it, then the problem must be your ground. Make sure that the ground is solid and secure, with these cars, best thing to do besides using the stereo's black wire is to ground the chassis of the stereo. A good ground is crucial for eliminating engine noise as well.

If it does NOT do it, then the issue is the amperage on the circuit of the ignition you are using. You will need to find a different switched circuit.

You can also use a multimeter and check out the voltage of the + switched circuit when you hit the brakes.

The only thing that makes sense regarding the issue of doing it while cold, is that the stereo is drawing from the battery and your battery is not well charged when cold, and it charges as your car gets warm; sign of a weak battery (this is pure speculation though)

Cheers, Edward

[Mike87]

I ran into this problem with my son's 320i. I installed additional brake lights in the empty pockets in the stock tail light lenses. It resulted in the stereo cutting out while braking. What I discovered was that the power to the stereo was tied to the same circuit as the power for the brake lights and the lights were drawing too much current shutting off the stereo.

I ended up using a different circuit for the stereo that was not tied to the brake circuit and the problem went away.

[DUDONLY]

Also check the speakers if the speakers are touching any metal.... they will produce these symptoms.

HtH

[josh72ooh2]

Thanks guys. All very good suggestions.... next time i crack open the console, i will attack this.

[BDB]

Sounds like a ground issue

[josh72ooh2]

My car recently went through some accident repair and when i got the car back, 2 of the 3 relays i use for my alarm were fried. Also fried was my turn signal relay. I don't know if when they welded part of the car, it sent a current through the car... or what.... but this stereo issue used to happen *once* when i first started my car for the day.

Today, on my way to work, it happened about 50% of the time i hit the brakes. It was making me crazy while trying to follow a story on NPR....

As far as the stereo being on the same circuit, it is hooked up directly to that battery terminal. However, it could have something to do with the ignition switch that activates the stereo when the car is on.

I realized that my speakers have a foam baffle behind them so they shouldn't be touching metal.

I need to inspect that Ignition lead and the ground and probably find a new location to ground to.

Thanks for the advice.

-josh