Power Die Off

[SandyLee21]

Long time lurker, just joined up. I will post a photo of my 70 as soon as I figure out how to attach a photo. My question is I recently installed a new stereo and since when I hit the brakes or turn on turn signals radio dies off for a second. I have replaced voltage regulator and new Alternator (both stock specs). Neither helped, should I try one of the higher output alternators from Year One? The new alterNatori puts out 13 amps at idle, but power falls off from cruise to idle.
Thanks

[BLK 68 R/T]

Do you have the correct pulley ratio so the alternator is spinning fast enough? Also check your bulkhead connections for corrosion, damaged wires, etc.

[W4ATL]

Measure the voltage at the point you are getting power for the radio (accessory voltage) with brakes or blinker on. Compare it to the voltage at the battery with brakes and blinker. If it is a lot lower at the accessory point inside the car, look for a bad connection at the bulkhead, ignition switch or fuse block. Your ignition switch could be worn on the inside causing a voltage drop.