2004 F-250 6.0L Super Duty

A bit of history...
Had a parasitic draw that I was chasing for some time. I did drain tests, voltage drop tests, re-did (what I think to be) most if not all the ground connections, cleaned all terminals and ground connnections, replaced the alternator, bought 2 new batteries, replaced the starter, and even sprayed WD40 in my door latches trying to combat what I thought was a faulty VSM (was originally drawing ~.7mA, but seemed to have gone away). I also replaced door and window switches because a couple just wouldn't work.

Before I did all of that work, the batteries were sucked down significantly within a day and the engine would crank, but never start. Batteries often were drained down to 40-50% / barely 12.0V within 4 or 5 attempts of trying to start the truck. The draw on the batteries was TERRIBLE.

Since I did all of that work, the truck has started up fine with plenty of juice and things seemed to be looking up. It responded well on the road, and the electrical issues seemed to have faded. My draw tests were even down to .05mA. Batteries would hold a steady 12.5 to 12.7 overnight, and 14.x while running.

I took it to the store yesterday, came out, and the engine would not crank for nothing. Key on, start position, nothing. No attempt at cranking at all. WTF, I thought to myself (as well as no, no, no, no, no). Tried putting it in neutral and other gears, still nothing when attempting to start. I unplugged the yellow/blue wire to the starter and put it to the positive side of the battery, and it DOES crank. BUT, when I turn that key, I get nothing.

Turning the key makes a clicking sound in the relay, but I dont know much beyond that. Fuses are all ok. The instrument cluster comes on and all of that looks good and well. However.. this is where it gets really weird.. when I lock the doors via the door switch (had to leave the truck for a moment), the drivers side door lock pops up within a few seconds on it's own.

So. No crank with key, weird door lock issue, voltage seems fine at batteries/alt/starter... I'm completely at a loss as to why I'm not getting a crank now when everything seemed to be turning around for the better.

I have read that the neutral safety switch may need to be turned to align it correctly, as well as unplugging certain sensors 1 at a time (lcp, epb, maf, map, egr valve, fan) to see if I get a crank then. Beyond that, can anybody please help in diagnosing what happened within 30 minutes of me going into a store and coming out to find a no crank situation?

Thank you diesel community!

 

So if you go underneath and get it to crank with shorting the small wiire to 12volts will the truck run? it should with key on..
Did you short the starter solenoid big terminals on the right fender wall. That sends power down to that small wire.
You may just have a bad starter solenoid and has nothing to do with anything you did. Check connections on that solenoid.
Pretty sure an 04 is the same as mine.
Oh and .7 amps not ma.
ON EDIT YOU DON'T HAVE THE FENDER SOLENOID..
Check the relay thats clicking in the fuse panel..it may be bad. and of course that small wire for connection etc.
I would think the trans switch is before the relay but not sure..

 

https://www.ebay.com/itm/SS598-Start...wAAOSwZ8ZW2J77

Why do I see this?

 

If the door locks pop back up after a few seconds, the vehicles thinks the key is still in the ignition. It’s a fail safe so not to lock key in vehicle. If your key is NOT in the ignition and it’s popping back up, I’d put money on the ignition switch being the issue.

 

I'm not sure what you're asking here.

What trans switch are you referring to? The neural safety switch? Thanks for responding.

Key is in the ignition when this happens. Good to know it's just a fail safe feature. Thanks for the info.

I will test the relays and then try to pull codes, though nothing pops up as far as warning lights etc. Its so strange to me that it started running great and then BAM, no crank from a 30 minute store trip.

 

Not likely in this case, but for future reference I know someone who had a voltage drain. After about 3 days, the battery would be dead. The problem was a faulty 3rd party alarm system.

I saw another post where the voltage drain had something to do with a faulty tail light assy. Another was due to a faulty rear sensor and another was a chewed wire under the vehicle from a rat.

I have a voltage meter that will read small amounts of amperage. Disconnect one end of the battery and put the meter inline (in between) the battery terminal and the cable.

Set the meter to amps (10 amps first and then decrease). It will show you what the draw is.
Sounds like you already know how to test the current drain on your battery. Anyone reading this needs to be careful with the battery current (amps) check since you could do serious damage.

There will always be some drain/load since the computer and other electronics are always on, but it should be minimal.

 

Thanks for the input with the amp draw checks. I have performed 2 so far. The first time was reading around 1.5 amps (instrument cluster and VSM being the culprits). When I pulled those 2 fuses it dropped to almost nothing. As time went on, and I made a lot of fixes with cleaning up/replacing cables, cleaning grounds, fixing wires, so on and so forth. The 2nd amp draw test I did after all of these fixes showed a steady .05.. which I was happy with.

I tested all of my fuse box relays today, both from under the hood, and inside the cab. Most fuses read between 63 and 75 ohms, clicked on and off, and had an average of 0.8 ohms of resistance when hooked up to a battery.

There IS however 2 of them that are sketchy. 1 reads 64 ohms, the other reads 76 ohms on initial tests (good). When hooking up ground and power, they both open and close (good). BUT... after being hooked up to power and testing resistance, jump from around 4 ohms all the way to 190 ohms of resistance. I'm sure an ohms reading jumping around like crazy cant be good, right? I mean, these things go: 4, 32, 120, 60, 190, 13... etc..

 

Update:

After testing the relays and reviewing the fuse diagrams, I eliminated unnecessary relays and fuses from the panels (towing, tow battery, tow lights, heated seats, back defroster.. etc).

I re-installed necessary relays that I knew were good, and replaced some fuses that weren't broken, but looked dated. I put the batteries back in after a courtesy charge, and wouldn't you know it, it turned over and started right away.

1 day later, it held charge and started right up. Took it to the store (engine running while I went in, door locked of course lol) and drove it home. Waited about 45 minutes after I parked it back at home and tried starting again. Fired right up. So far, I believe it was faulty relays causing some sort of issue.

I will update over the weekend coming up on the latest status of the truck. If it still starts and holds charge, I'd say I made great progress, and will provide more detailed information. Thanks again for all the input.

 

For this instance, I'd say it was faulty relays 100%.

The initial electrical draw was fixed by doing amperage draw tests and voltage drop tests to narrow down the hunt. I also replaced a few ground wires and cleaned up the remaining that i didnt replace. A couple new batteries (since the old ones were sucked dry so many times), new alternator and a new starter for good measure all added up to a nicely running, and starting, truck.

No crank issues can be a number of things, but for me, it ended up being several faulty relays.

Thanks.