F350 Electrical Gremlin

Boss just called me...

His 08 F350 Superduty 6.4 is having electrical issues.

Said the instruments, dash, lost power, radio went off, AC blower went off. Then everything came back. Did this several times while driving, engine never stopped.

But what is strange, not everything happens at the same time. Sometimes the radio would quit, but the instruments kept working. Sometimes the blower and radio would quit, just random failures. One time the radio quit, and lost the time and presets.

I was looking at some online forums, Youtube, etc. This was a common problem with older trucks, but seemed to be limited to the generation prior to this model. The problem was with a relay on the instrument panel.

Last Thursday I replaced the alternator. But all this started Saturday. I'm really trying to believe there is no relation. The alternator was straight forward, lots of stuff to remove to get to it, but I don't see any wiring getting crushed or disturbed. I had the batteries disconnected, and one battery out, but the only ground was the battery cable itself. The alternator was replaced as soon as the charge light came on. The batteries were not discharged, the truck was not jump started, or the batteries charged.

So this is what awaits me Monday morning...

Any ideas?

Thanks!

Chassis to body ground strap. Possible other panel grounds as well. Jim

I agree, that sounds like a Grounding problem. Physically remove any grounding straps/lugs and check for any dirt/rust/corrosion.

Relation being possibly one of the alternator being grounded through the mounting bracket. R/R it again. Scrape the alternator mounting flanges of any paint by the re-builder, clean the mounting bracket also. Wouldn't be the first one to have this problem.

Had the same problem with a chev [things off/on/engine shut down and re-start by itself] found that the ground connection at the battery was dirty/corrosion inside the factory made terminal[ high resistance]. cut it off and put a normal strap and bolt terminal on.
all good since.
hope it helps.

there are three main plugins on the l ft fender liner area that get corroded on these trucks, especially if the cab has been off & not plugged back in tight. Have found this several times to be the cause of strange problems

My first thought would be an ignition switch.

Any aftermarket accessories on the truck?

Anything getting warm/discolored on the fuse panels?

Being that you can easily listen for the blower and radio I would start it up and turn them on.
Next do a wiggle test starting with the key then whatever switches, plugs, harnesses, fuse panels etc that are associated with the systems that are shutting down.

One other thing to check is the output of the alternator . Some ford products turn off the dash if alternator is overcharging. Don't know that would be the case with yours but something to look at. jstpa