Quick question.

I am trying to install a new radio and speakers on my RX7 with my own wiring.

I only wanted to use the stock wiring that power up the radio.... but the B+ wire (blue with red tracer) has been cut somewhere because I do not get B+ there.......

Can somebody tell me where does it go so I can follow it? I noticed that the "AUDIO" Fuse (20A) powers the Accesory B+, but I do not know if that one also powers the constant B+....

If I run a custom B+ source to the radio, where can I get it from? Would I need a fuse?

Thanks!

 

1. Yes, you need to fuse. Heaven forbid that wire shorts to ground it instantly heats up until it burns to a crisp from the infinite current. 10A is sufficient.
2. The most straightforward place would be from the battery, however you can find it at the ignition harness.

 

Thanks, you confirmed all my doubts.

I would not like to carry a wire all the way from the battery since it would be just hanging on the engine bay... Which wire from the ignition is the one to tap into? And also, will the extra amperage do anything to that wire?

Thanks!

 

The ignition wire should be black on FC's and black/green on FD's at the ignition harness. It would be in your best interest to test with a DMM first to verify you are making connection at the proper wire. The additional current draw from an aftermarket radio is usually at best 10A; the wiring at the ignition harness are all high current heavy gauge wires so there is no need for concern.

 

I checked the wiring at the ignition, and the only one that had constant B+ was a big white wire with red tracer....

I also saw alldata saying that the wire would have to be black... so I do not know.

 

Trust your meter. I've encountered HUNDREDS of situations where Mitchell1, AllData, Directechs, etc. has been wrong about a wire color, polarity, or location.