I just installed a new stereo and amp into my 71 chevelle. The problem is, when the engine is running at low rpms, the stereo will turn off and then back on. It will keep doing this until I rev the engine. It also turns on and off when the key is turned to ACC. I don't think the stereo was getting enough power and initially thought the battery or alternator was the problem but both have been replace with high power models. I assume theres a problem with the stock power cable? Any help?