ACM Wiring and ACC Sense Voltage For Market Radio

[jisbell5]

Hello,

The ACM on my 2013 Ford Fiesta S model went bad. I am trying to install an after market radio but am running into a few issues that I hope someone can explain. I have verified 12V and ground on the Meta adapter harness required for installing the after market radio. I ordered a 2013 Ford Fiesta Wiring booklet double check the wiring. I found the Meta cable did have the ACC sense line on the wrong pin which I fixed. The problem I am having is with the ACC sense voltage from the ignition switch. I measured the voltage as 3.9-4.1V when the ignition switch is turned onto the accessory position. The aftermarket radio is expecting a 12V input on the ACC sense line and therefore does not power on the radio. Should I expect 12V on the ACC sense output to the ACM? Any help would be greatly appreciated. Unfortunately the wiring booklet only gives all of the information regarding connectors, wire colors, etc but not voltages on any of the circuits.

 

[scotman]

You need to consult with a person who has done aftermarket radio installs in the Fiesta. I think there might be some confusing terminology differences in describing certain circuits. I would look at an installed audio unit as always being "on" in the sense that what we used to call the "keep alive memory" is maintaining settings.
I don't think Ford developed this system with the intention of it being friendly to the idea of being easily changed. Which is probably why you are having a lot of trouble.