Hey Zorro, you've got a low voltage problem. Forget the OVP. ABS light coming on? Radio shuts off? Turn signals INOP? Low voltage. As soon as you switched off the ACC( which can draw quite a bit of current )the voltage rises enough to allow everything to start working properly. The OVP has nothing to do with the radio or turn signals. Regardless of how old/new the alternator is, make sure it's working properly. Also make sure the battery is o.k. Let us know how it goes.