Update: WATER=Yes. TruckWent BERZERK: Advice? (1 Viewer)

[Markuson]

What the heck??
2:00AM... Shut off truck 8 hours ago...

In bed hours later. **CAR ALARM finally gets my attention after assuming it was someone else. Finally go look, and it’s my truck going totally nuts! Not just the alarm...

-I come out, lights are flashing, horn honking.
-Hit unlock on my FOB and it stops...

BUT...-Then I notice fan noises, a weird click every 10 seconds or so and then three beeps (like the beeps a fob makes when lock/unlocking, but three beeps...not one or two.

-Open door and hear the AC fan turning on...then off.....then on...off...

-Start engine, it starts.
-Shut it off.... Fan starts doing its on off thing again.

-Open hood and I can hear something turning on...off, etc. again, completely on its own.

-Disconnect battery and wait...

Reconnect, and it starts the AC fan cycling again.

-Disconnect for longer and reconnect. No fan weirdness this time, so... Start it up...turn it off... Weirdness starts again.

**Plug in my OBD2 scanner...takes **forever to initialize.** Says 9141.

-Try it again and it connects this time.

-Several more attempts to see how hard going on...and now the engine won’t start AT ALL. Dash lights up...controls work...but no start.

-Total Twilight Zone stuff the the truck doing weird all this on it’s own.

-Finally I Disconnect both batteries and leave it alone now and there it sits.

Seems like the computer just went totally berzerk out of the blue...8 hours after a perfectly normal trip.

ANY CLUES OR THOUGHTS??

Fried computer?
(Why??)
Something else?
Thanks for any input....

M

 

[desmocruiser]

Sorry to hear, at least at home and not the trail!

It sounds like you are on the right path with one of the computers. Do you have anything added such as remote start etc. that could also connect to the alarm, AC fan, etc.?

No visible issues/burnt smell with the fuse/relay areas?

 

[Reckless]

 

[Dre01SS]

Wonder if the BCM may be going bad?

 

[CharlieS]

Possessed?

I've read about water intrusion causing weird computer issues. Any recent water crossings? Windshield replacement that may have leaked? Clogged sunroof drains?

Maybe see if there is a computer that controls all of the above and check and clean all connections, plug the battery back in and try to diagnose with techstream and the fsm?

The security computer/module seems like a prime culprit, although I have no idea where that is.

It's harder to do systematic troubleshooting with the alarm blaring,

 

[04UZJ100]

I know you have a fair bit of electronics on your car.....

Can you wire one battery as it would be in “stock” form and go from there?

 

[PDoyle]

Got any pics of your dual battery set up?

 

[gaijin]

Good morning, @Markuson !

This is just a SWAG, but for some reason my intuition is strong on this one:

Isolate your main battery if you can, and replace the alternator diode with a normal fuse.

Fingers crossed

HTH

 

[CharlieS]

Good morning, @Markuson !

This is just a SWAG, but for some reason my intuition is strong on this one:

Isolate your main battery if you can, and replace the alternator diode with a normal fuse.

Fingers crossed

HTH

I hope you are right.

I don't get how the alternator diode would come into play with the vehicle not running though...? I'd think it would manifest itself as a poorly charging (lower or no voltage) to the starting battery while running.

I agree with others that isolating the add on electronics from the factory electronics is a good troubleshooting step. Minimally it divides the problem in two, so you know which direction to troubleshoot.

 

[paulunm]

Possessed?

I've read about water intrusion causing weird computer issues. Any recent water crossings? Windshield replacement that may have leaked? Clogged sunroof drains?

Maybe see if there is a computer that controls all of the above and check and clean all connections, plug the battery back in and try to diagnose with techstream and the fsm?

The security computer/module seems like a prime culprit, although I have no idea where that is.

It's harder to do systematic troubleshooting with the alarm blaring,

Yeah, it just rained in SoCal for the first time in months- so that would be my guess. Leaking windshield of sunroof drains clogged?

 

[bloc]

It is very, very easy to pull the trim at the edge of the carpet on the driver and passenger side door openings to look for water in the floor harness well. I'd do that along with isolate electrical accessories.

Edit: also look for rodent damage.

 

[PDoyle]

I only ask for pics because even the smartest man can overlook things.

 

[RET2]

My guess is water intrusion, where is the question. But where it went after entry may be the real issue.

 

[sdnative]

Probably related to the rain we had yesterday. Look for water intrusion, wet carpet, etc.

 

[RobW0]

I would look at a problem with water. I know you have had a fair amount of rain there the last couple of days. Maybe a leak from the rack you put on a couple of months ago? Hope it is not too serious.

 

[Markuson]

I would look at a problem with water. I know you have had a fair amount of rain there the last couple of days. Maybe a leak from the rack you put on a couple of months ago? Hope it is not too serious.

Definitely water in the driver pillar... Ugh...
forward/left of the driver footwell.

 

[Markuson]

So... Who’s got a great trick for evacuating water in that jam-packed corner under the pillar?

I’ve pulled quite a bit out with a big syringe... but very tough to access even with panels off.

Not sure how it got in...but it’s outside...not gonna move...and more rain on the way. Ugh.

 

[bloc]

One user here had a chassis sealant defect that let a bunch of water in. I’d think if you had that you would know by now though.

Possible it’s the rack, windshield, the usual places. I’d pull the body plugs down in that area so any new water that gets in at least won’t pool up. Also try to determine if any modules under the dash and kick panel are getting wet. If it’s from the rack or windshield or even that defect it *could* be running down in a way that doesn’t hurt anything directly, but the damage occurs when it pools in the well there with the harness lying in it. Or, if a windshield, it could be falling directly on the BCM or something important.

Pulliig the plugs should stop water collecting, but some tarps over the rack, windshield, and cowl should prevent water getting in in the first place. I’d still pull the plugs though.

 

[04UZJ100]

How do you think it got there?

 

[RobW0]

So... Who’s got a great trick for evacuating water in that jam-packed corner under the pillar?

I’ve pulled quite a bit out with a big syringe... but very tough to access even with panels off.

Not sure how it got in...but it’s outside...not gonna move...and more rain on the way. Ugh.

Ugh is right. I would look at the rack mounts for where the water got in. I would say use some fans, dehumidifier and may some DampRid.