So I have a 2003 Ford F150, I got a new Kenwood stereo to replace the manufacturer one. I got it out and got everything unplugged then hooked the new stereo up with the Best Buy wiring harness. The new one has no power and wouldn't turn on so I tried to hook up the old stereo to start troubleshooting and now the old one has no power and won't turn on either. However it was working before I took it out except the cd player was not operating. I checked the fuse box and the fuses that were in it looked fine. I checked the fuses #8,20,and 30, they all are in the right spot with the right amount of amps. I am running out of ideas on what could be wrong. The factory wiring harness looks to be in great working order.


If you have any other ideas please let me know.

 

I would almost bet the fuse is blown. Check all of them.

 

Did you disconnect the battery first ? If not, it's worth a shot, disconnect it for a little bit. If you remove both cables reconnect positive first after say 15 minutes or so. Do this AFTER you have checked all the fuses.

 

check fuse
check voltage and ground on harness pins

are you colorblind and dont know blue from black?

 

Yank the radio and check voltage across your constant hot 12V to ground, it should be 12V ish. Then verify that your switched power will be at 0V. Then turn the key on without starting the truck. Voltage for both should be at 12V.

Key should be out of ignition
Constant power > Ground, should be 12V

Switched power > ground, should be 0V

Turn key to "on"

Constant power > Ground, should be 12V

Switched power > ground, should be 12V