2004 Ford accessory power delay issue
 

Hope you might be able to help. I have a 2004 f150 supercrew lariat. 5.4L. It has the 6 disc audiophile head unit. I have successfully heard music through the speakers for about 30 seconds today, before it shuts itself off again. I cleaned all of the contacts, have power to purple wire green stripe, pink wire red stripe. solid ground through black with light blue stripe. All of my fuses check out good. I have a volt reading of 14.37 volts at the radio harness connector. I have a good R02 relay. I cleaned every clip in the entire harness under the dash. And I do mean every clip to every harness. I even pulled the fuse block and cleaned the connections. I stopped short of pulling the circuit boards apart though. I wasn't sure if it would stop working if I went too deep. Anyhow, everything works, all lights, all connections in the cab, every system of the truck works. all except the radio. Even the head unit is good, and I can repeat the problem by unhooking the radio harness and plugging it back in. Radio plays for 30 seconds, then stops again. I can hear the station, switch from am to fm, change stations, during that 30 second window. I'm guessing something to do with power regulation from the instrument cluster. Or accessory power delay, but not the relay? Any advice? I had the famous ford failed firewall seal water intrusion. I stripped the entire cab and cleaned everything very well. As in a week worth of making sure everything worked after being reassembled.

I'm not sure if I can be of any help here, but when the radio quits did you lose power to the unit or did the radio just quit?

Some vehicles from about 2003, On have a CAN bus system. This system contains several modules of which the radio might be one of them.
If it worked fine before all the work was done that is one thing if not, the radio may have a problem and sometimes a capable scan tool is required to determine what is going on.

I've been farting about with it. Popped the dash yesterday above the instrument cluster, checked for continuity throughout the 2 pin connectors. Plugged it all back together. No difference or change. I popped the radio harness supply connector apart and got the radio to function for about 30 seconds. Sound and all. Truck was running for this. Radio quit again after 3 solid "blips" (on/off) by itself which suggested it was the overload protection relay from the cluster. Today I decided to slap the seats back in. I had the truck running for awhile, torqued the seat mounts back down. Shut the truck off. During the truck running, I had fuse 31 pulled. I put 31 back in and the radio started working great. Found a station, tried to switch to CD and it said "CD error" on the display. I turned the radio off manually via normal power switch. I switched it back on and nothing. I checked at the CBJ. No blown fuses. I pulled 31 and put it back in. Radio worked briefly. I figured maybe a loose connection in the CBJ. I've removed the CBJ, broke into it and stripped it down to the circuit board. Thing looks brand new. No corrosion, or burned spots on the bread board. I'm still putting it back together at the moment. Since it looks as good as it does, and everything works, I'm now to the conclusion either positive backfeed short, possibly from a liquid crossover when I shot it all down with cleaner. Bad battery saver relay, (R304) or a bad instrument cluster power managment module. I keep seeing a brief "low oil pressure" signal through the instrument cluster display, and i have had the oil pressure gauge either peg at max, or no response at all. The gauges are all responding appropriately since I started cleaning and putting stuff back though. Not one hitch in any system but the radio. I did find a 2.3 volt positive feed through the negative side of fuse 31. I'm still stumped about that. I found it before I pulled the CBJ. So hopefully it will go away with install. Thanks for replying.