Just got hit by moderate floodwater in SE Louisiana again. Had to drive through roughly 2 ft of water to get to my daughter. Took it super slow but when I came out the other side it was driving really rough. Didn’t run it for two days to let it dry out, but it was still driving the same. Weird electrical stuff started....keypad died, lights would flicker and weaken. Service light came on and diagnostic said O2 sensor but that wouldn’t explain the issues. 4 days since the flood and after 2 days of driving it, it’s now DEAD dead. I’m sure there’s a technical term but that’s all I’ve got at the moment. Any ideas of where I can even begin to troubleshoot? Thanks in advance, Mindy

 

Floodwater should be covered by your insurance. Contact your auto insurance and let your local dealer handle it.

 

Not when you just have the minimum. Thanks tho.

 

O2 sensor take in air samples around the wire. By submerging the O2 sensors you might've ruined them. My other half did this to a Mustang GT we had and I had to replace all four O2 sensors before it would run right again.

 

several connections are underneath the vehicle they mightbe full of water and need to be disconnected dried greased and reconnected
perhaps water even splashed up onto motor
kinda hard to say what exactly
but O2 sensors should not create a no start issue
check air filter and air box dry it out if needed
water might of had debris in it and something got logged in crank sensor
most likely a fuse would protect anything so check fuses if one is blown investigate why first before just replacing the fuse
a blown fuse or relay is my bet
but most likely the security is tripping
obviously check alternator and battery
main fuses by battery

 

Thank you! That gives me a place to start. Much appreciated

 

ive seen a tail light full of water ...buddy replaced the fuse with piece of metal because fuse blowing (every time he hit the brake) untill sitting in traffic started a small fire omg

 

On a bone stock first gen with 265/75/R17 tires, 24" of water reaches the top of the rims. With how high the water was when you went through it, it wouldn't surprise me if that was the last nail in the coffin for the entire grounding system.
Quite a few things are grounded behind the Kick Panels (Body), including the PATS system. There is a ground strap between the frame and body just behind the passenger front wheel. When I redid my 97's grounds in 2016, this one broke in half as I was just LOOKING at it. If either one gets sketchy, you're dead in the water because the PATS system will panic. The other thing to keep in mind is that there are other things grounded to the frame in the rear of the truck too. IIRC, it's in front of the driver's side rear tire (everything in the back), and one behind it (trailer harness).

An engine can still run with dead O2 sensors, the PCM just defaults to the "oh s**t" settings in its fuel table. But if your engine ground is failing, the first symptoms will be seen in the ignition system because it is the heaviest, most dependent circuit that relies on the engine ground. The biggest falls first.

I'd suggest going through the truck, rehabbing every single ground and replacing those garbage ground straps with proper 4awg cables. Each one needs BARE SHINY METAL. And for the love of all that is Ohm, Watt and Volta, stainless steel bolts, new terminals and dielectric grease.