Just replaced an 80's era blaupunkt cassette radio with a 73 motorolla radio. The 80s radio had two hot wires, one from the battery somewhere, and the other wire going into the fuze box, spliced into the ignigition wire. The 73 radio has only one wire for it.
Which wire should I hook it up to for power, and which would likely cause less damage if for what ever reason something shorts.

Thanks

Tod

Likely one is for a power antenna or something to keep it warmed up or an accessory that's not obvious ???

....Motorola may have the wiring diagram still available. Try and contact them.

Newer radios have at least 2 power inputs, one is switched and one is straight +12V. The straight +12V is usually a heavier gauge wire to power the amps in the radio.

The switched +12V (from ignition) is usually a thinner gauge wire and is used to turn electronics in the radio on and off with the ignition key.

Earlier radios have just one switched +12V which carries the amp current and turns the radio on and off.

If the "new" radio does not have a digital clock or anything that would require it to have power when the ignition is off, I would say having it switched will work.

Mike may be correct about the antenna but that would be an output connection that goes hot when the radio is turned on. Probably one is to be constant hot to keep the memory programed and for the clock. The other is switched by the ignition. You may short them together. I had done this and the radio was wired unswitched. I had problems with the battery running down. The radio will use some power when off. I think in my case this was too much power drain and in a few days..dead battery. I have a new radio and one wire is switched and the other is not. No more battery problems.

If it doesn't have electronic settings, which since it's a 73 I doubt it has, you should attach it to the switchable line... Constant power line is usually there only to maintain settings... Unless you want to be able to turn your stereo on and drain the battery without a key in the ignition...