I'm new to this forum and to my recent -87 Carrera. The seller had a new radio put in the car and it works fine (most of the time). However, when i accelerate (rev up) the power to the radio shuts off. While this certainly has some advantages in that I get to listen to the 3.2 instead of my 7-year old's pop music, I can't help but being a bit puzzled by it. When I ease off the accelerator, the radio comes on after a few seconds.

I have checked the cables and don't think it's a connection problem caused by the physical movement of the car...

Can this have anything to do with the alternator/charging? Can the car somehow "consume" all the elecrical power in the acceleration?

Needless to say, this doens't happen to my 997...

 

this could be very serious and i suggest you stop driving immediately until you check a few things.

get a voltmeter and hook it to any 12v line. you can even get o es that plug into your lighter. watch that voltage carefully.
your radio. may be going into over-voltage protection mode. if you are above 14.5v you could be overcharging. this will boil your battery and spew acid into your car. if you have smelled rotten eggs you are too late and should immediately flush with baking soda and water to neutralize the acid.

i hope its not this but it sounds familiar.

if you find it is overcharging, it is alt rebuild time (regulator)

 

Overvoltage condition will surely blank a radio on most (not all) occasions. Like Ice states: you wanna' know the alt/reg is doing it's job under load.

You certainly don't want to boil a battery (and all that goes with that).

First things first.

Best,

Doyle

 

This is a feature all 911's should have; radio shut off during acceleration! Roll down the windows and listen to the music coming from behind! The volume **** is under your right foot!

 

When this appended to me it was my vr
Going bad into overcharge.

 

Measured the voltage yesterday. First run I had a solid 14.5v coming out of the cigarette lighter according to my volt meter. Radio was on and working fine through acceelerations. Then I stopped the car and let is sit for 10 minutes and tried again. This time, I got readings as high as 18.5 v and - needless to say - the radio turned off in every acceleration. Drive lasted 5 minutes to the workshop where the car is now.

Oh, I blew a fuse since I bounced the volt meter sensors into each other when removing them from the cigarette lighter...

Thank you iceman, Doyle and gang. Spot on analysis. Will keep you posted.

 

In case anybody comes upon this thread while trying to diagnose a similar problem in the future, the way to measure the voltage coming out of the cigarette lighter is to get an accessory plug you don't really care about, cut off the leads, strip them, clip the leads of you voltmeter to the leads you've stripped, tape them up so they can't short, and then you can read the VOM while you're accelerating, assuming you're in a safe enough spot on the road, or you have a passenger to do that. And then you won't accidentally cause a short by touching the probes to together in the lighter.