Need help with electrical issue
 

I have a 07 with a 5.4. I hard wired a dash cam system that I had been using plugged into a 12v socket. I found that the socket stays hot all the time and the camera would drain my battery if I went several days without starting the vehicle. Using a fuse splitter, I wired the hot lead into fuse slot #31 which powers the radio. when I turned the key off the radio shut down but the camera stayed on. I then found that there was still voltage on the circuit so I moved the splitter to slot #22 which is for delayed accessories. It seemed to work fine but now the vehicle will not crank. When I turn the key, I can hear the starter relay clicking in the fuse panel but that's it. This is with an auto transmission and I tried it in neutral and even in gear and I get the same click. Disconnected and reconnected the battery and still no luck. I disconnected the camera and checked the original fuse and it's fine. Any suggestions? I'm stuck!! Thanks in advance, Dave

First start with battery. Does it pass a load test? Make sure you have good power before you check anything else.

Ok, the battery tests good. Any other thoughts?

I've confirmed that with the key turned over, there is no voltage at the starter wire. Thanks again.

Still looking for ideas if anybody has any. Truck is still dead in the driveway. Thanks

Have you disconnected the dash cam where you wired into the fuse panel and tried to start it? It could be pulling too much juice where it's wired in. Did you splice into the wire or use a spade connection that pushes into the fuse? Work backwards from when the no start issue began after you moved the wiring.

If all else you could rewire it to the radio fuse where you had it, then through a rocker or toggle switch and shut off the switch when parking.

Have you checked the fuses and relays? Checked the under hood power box fuses? There could be an in line fuse going between the alternator or battery that blew.

If you're missing the owner's manual you can download it from Ford's website. You'll need that for fuse location/identification (though it sounds like you already have that).

Thanks very much for the reply. The camera has been disconnected. There are fuses that have no power to them including #34 which powers the PCM. The only "fuses" I can find in the engine compartment are the fusible links in the alternator harness. Do those feed fuses inside the vehicle? Should all of the fuses in the panel have power with the key on? There are a number of them that do not.

There should be a some what large box near the front mounted on the fender which is the PCM (I believe it's called the primary control module) with more fuses and relays.

That actually feeds the interior fuse panel and has the pirmary fuses for the fuel system, emissions system, lighting and such. There are a variety of relays in there as well for many of the same system.

Have you checked the owner's manual? It's usually the last page or 2 of the fuse section has the PCM layout.

If you have an electrical meter there are several good videos that demonstrate how to test a relay.

I'm not sure how else to proceed other than pull each fuse one at a time, check it and put it back in until you find the bad one. There are some fuses that won't have power because the go to options you don't have on yours like say driving lights or individual climate controls but the fuse for it is there.

Another idea is you starter and/or solenoid may have chosen this time to fail as well.

If you have a fender mounted solenoid you can test it by crossing a screwdriver briefly across the ends of the large bolts where the larger wires connect. If the starter turns the solenoid is bad.

You can use this method on a starter mounted solenoid but it's a little difficult given the space to work in. If that one is bad you have to pull the starter to remove it and call around to make sure the solenoid is available. Last one I did I wound up replacing the starter (which comes with a new solenoid) since every parts store I called had to order the solenoid.