Annoying stereo shutoff when starting

[StevieC]

The 1amp will be more than fine for the Diode... The relay is good too.

Sorry for the late reply I was cutting open a Fram filter for another thread here...

 

[chevrofreak]

It works, but it doesn't. I think the battery voltage drops too much. I'm going to test tomorrow using jumper cables and another car.

 

[eljefino]

Trace your ignition switch, there are often at least TWO ignition hot wires, (plus the ACC wire!) one goes to the blower motor and cuts it off when cranking, the other does stuff vital to running and is hot in RUN and CRANK. Set the radio up off a relay off this lead. That will take care of the cranking part.

To keep the radio alive when the key is off, you could set up a second relay off the brake light switch. Should have the brakes on anyway when you're stopped and killing the motor. Once you turn the key back on (but not yet to start) it will take over and you can release the pedal. Put the relay in the trunk so you don't hear it click. With this plan you'll need two relays or it'll back feed and keep the motor running.

If it's an aftermarket head unit, most of the time they get most of their amp power through the always hot lead and just use the ACC ON lead to run an internal relay or logic. This counters stock radios that usually get amp power through the ACC feed. The sizes of your fuses will tell the story. (Have seen 3 amp "dome" fuses blown by aftermarket radios.)

 

[chevrofreak]

Bought a new battery today, which didn't help. Even when I had the two batteries jumpered together.

I ordered a 5 farad capacitor. I hope that fixes it.