Hey folks, I'm dealing with storm prep and having trouble finding ideas on this, so I thought I'd hit up the brain trust. ;) Ideas and links to prior discussions are welcomed (appreciate it!).

I have a 2004 4R that leaked through the sunroof over the past week of rain ahead of hurricane Milton (inbound, prep is my main concern right now). I'm not sure whether the water overflowed the gutter only, or the drains as well. I found the mechanism fairly rusted and lots of rust in the gutter that seemed to be blocking the drain. The headliner was damp and the floor was soaked (about an inch of standing water in the drivers side footwell, whole floor area is wet).

OK, so the real issue -- the vehicle won't turn over. The battery is good. The starter relay clicks when the ignition is turned. I also swapped the starter relay with the fog relay, no change. There is no sound from the starter or starter solenoid. I got the vehicle towed home and into the garage and vacuumed out all the water from the sunroof gutter and floor. It's got fans on it now and shouldn't get soaked during the storm (provided the garage doesn't break, and that would change my priorities quickly).

Anyway, I'm leaning toward a failed starter or water intruding on something I'm not aware of. Given the scenario, is there anything I should check or test prior to replacing the starter?

Thanks in advance, and stay safe to the storm impacted ppl out there.

I'll start with removing both pos & neg connections @ battery and do a good clean to ensure good contact upon reinstall. Next turn on head lights and try cranking engine. If lights dim and starter relay clicks , your battery is low on charge or not as good as you had thought previously and do not have the reserve to turn engine over.

I did try this prior to towing the vehicle. There was no dimming of the headlights, which is what made me wonder whether something important suffered water intrusion.

I also checked all the internal fuses and all the external fuses that looked likely to contribute (it was raining, anything related to starting, ignition, ECU I checked).

I attempted jumper cables, but there was no indication of low voltage/battery issues. It didn't even spark when I connected the cables.

Current status is battery disconnected, tested and charged with my charger. It's sitting at 12.8v.

V8 or V6?

When you say you checked the fuses, how was that done, just visually or did you do a continuity test with a multimeter?

make sure that battery is holding. check the ecm fuses some of them get corrosion and loose connection. had a no start issue when i put a new engine in, even had someone come out and said ECU was messed up. my boy happen to come by wiggled a couple fuses and boom she started right up. hopefully its something as simple. were you having start issues at all before??

Good point, visually mostly. I did some swapping of like fuses to verify the critical ones were really good. I’ll go back through them with a meter now.

Good point, thanks. While I’m verifying them all for continuity I’ll wipe the contacts with sand paper, just to make sure. Will have an update by tomorrow.

I still would like to know which engine you have, V6 or V8, it makes a big difference when accessing, troubleshooting and working on the starter?

Apologies, it’s the v6. Doesn’t look terrible to swap if that’s the most likely culprit. I’m worried something got wet though. I can’t find any indication of what yet, just was a really wet truck yesterday.

It's good you have the V6 with easier access to the starter.

Have you loosen the cables to the starter and cleaned and retightened them, if not might be a good idea to do so?

Not yet, adding it to the list for today. I want to let it continue to dry for another day before attempting to start. It's still damp at this point, but much better than it was. So today I will:

Check continuity on all fuses, sand contacts, reinsert. -- DONE. I found a burnt 20A fuse in the PWR Outlet spot on the internal panel (should be a 15A, replaced it). Otherwise no issues.
Sand battery posts and cables. -- DONE. All shiny clean, battery is holding charge. I ran my inverter and shop fan off it for about 10 mins and it dropped .2V, which seems about right. My charger still says it's good, and it's charging back up now.
Clean/sand starter cables, verify tight connections. -- Likely tomorrow. Need to put the truck front on jack stands for this and I want to test the front sunroof drains first.

Once the storm passes (late tomorrow or Friday AM) I'll reconnect the battery and try to start it.

Sorry for the slow update, I had to leave town for a week for work. Today I checked the starter connections and that looks to be fine as well. I'm waiting for some help so I can check for voltage at the solenoid. I hooked the battery back up, verified it again with my charger/tester, and the symptoms haven't changed -- still no crank, no click. I can hear the hydroboost pump for the brakes run for about 15 secs the first time I turn the ignition on.

I've been looking to prove out whether this is the starter, ignition switch, or the ECU. From what I've read the ECU provides power to the solenoid via the relay, and in a bad ECU situation I should be able to put 12v on one of the relay connections to cause the starter to engage and turn over (which would prove it's good). But I haven't been able to find a diagram for how to do that with this truck. Has anyone seen or done that? If you can confirm I'm wrong with this approach, I'll take that too.

Thanks!

Some things to try.
1. Try and whack the starter a few times with a hammer - kind of gently but firmly. If it fires up, replace the starter.
2. Check DC Voltage on the small control wire at the starter while cranking the starter. If you don't see 12V, problem is on the control side upstream. Make sure that wire is well connected to the starter. Make sure you have 12V on the big wire terminal even without cranking. Make sure that wire is well connected to the starter.
3. Bypass all upstream controls by running 12v to the control wire terminal at the starter. This should close the solenoid and you should probably here it click if it is good. If it cranks, problem is upstream. If it doesn't crank and you think the solenoid is closing, check voltage drop from positive battery terminal to big wire terminal on the starter while trying to crank. Should see less than 0.5 drop. If more, check connection at battery or perhaps wire is internally damaged. If no excessive voltage drop, replace the starter.

I appreciate it Buckaroo. #1 I've tried already with no result. #2 and 3 are queued up for tomorrow when I'll have a helper. This should prove out whether the starter is good. If it is, then I need to figure out whether the ignition switch or ECM is bad. If nobody posts one I'll do more searching today on the pinout for the starter relay socket. Low voltage there seems to be indicator of a failed ECM, no voltage there seems to indicate a bad ignition switch or possibly the transmission lockout.

The transmission interlock circuit is always the thing I check first. Sometimes, it'll start in neutral ("N") or fiddling with the transmission selector. With the parking brake on and wheels chocked, of course.