Engine shut-off issue: a saga

I will try to make this convoluted thread succinct.
Several MONTHS ago I changed out both headlamps in 2012 4X4 Off Road Tacoma.
To accomplish this on side 1, I disconnected and removed battery.
On side 2, I attempted to remove washer reservoir by removing housing screws to frame and disconnecting pump motor wire harness but disconnecting the harness was too difficult and I siimply pushed the reservoir back until I could get my hand between the reservoir to replace the headlamp.
OK
When all back together -- including a THOROUGH cleaning of the battery terminals and conductors -- I tested the lamps. All good.
Except thereafter 3 warning lights came on: vehicle stabilizer, ABS, Brake. And they stayed on. Of course I took it to my mechanic and he put that diagnostic thing on, found nothing, and told me it might be that "the computer" just needed time to recalibrate. People are limited but I trust my mechanic. Off I went.
The warning lights never went off.
Weeks, maybe months later, I had the tires rotated at Les Schwab and naturally they informed me the warning lights were on and offered to inspect.
Interestingly, the LS guy told me -- he wasn't real sure -- that he picked up something in the washer reservoir that might be acting up, like a sensor failure. I had messed with the washer sensor and told him that might be helpful information.
Not too soon after, I was driving the interstate at 70 mph and over a bridge transition and the bump shut my engine off temporarily and the warning lights went off.
And stayed off.
But the engine kept shutting off whenever I went over a bump. If I went slow, it seemed the engine would shut down and I'd have to pull over and restart. If I went fast, it seemed the engine would shut down, stumble loud and restart.
I once opened the hood whiile the engine was running and dropped the hood and the engine died.
Now it seems like a loose connection, a serious loose connection.
But it also seems odd that the warning lights and the stumbling engine and the on again off again warning lights might be connected.
Without knowng, is there a possibility that some "sensor" in the washer reservoir is connect to something that could shut the engine off?
(Sorry about the long story)
Any insights anywhere?

 

There is no sensor in or near the washer reservoir, there is a stack of grounds right below the reservoir though that may have been disturbed and would be worth investigating.

 

Thank you. You're educating me. However I'm unfamiliar with "a stack of grounds" terminology. How would I look -- possibly reconnect (?) a stack of grounds right below the reservoir. Maybe this is what the Les Schwab associate was alluding to when he said "he wasn't sure but it seems to be coming from a reservoir sensor." I couldn't understand that "sensor" thing either. Back to the point: "Stack of Grounds." Could disturbing the "stack of grounds" potentially shut down the engine? And again, thanks for the quick reply

 

Remove the washer reservoir to the extent possible and see if there are ground wires attached to the body or frame, or both. See if any are broken or loose. They would be black wires, since that's ground for 12 volt systems. With of course a few exceptions, but I'd still be looking for black. It seems you live in places where road salt is used. I'd also look for rusty connections.

 

Kind of hard to get a good picture but these are the grounds I'm referring to.

 

Would be Ground point EA on the diagram, alot of stuff grounds there.

 

Thanks to Dm93 & HisDad for their response and input.
Here's an interesting thing, again: Went out to check the "stack of grounds" (I understand what is meant; it's now obvious). No movement, tight. Futzed around with the harness to the wash reservoir, again, too. Of couse I have no idea what's going on behind the insulation, nothing seemed to change (particularly dash board warning lights). Engine was running. I dropped the hood (covered my ears for the drop) and the engine, again, weakened, slightly stalled but did not shut off. I did that two more times and each time the engine weakened, slightly stalled, but did not shut off. Interesting. I'll continue in a while to check the grounds. One thing I noticed: I've cleaned the battery terminals and cables THOROUGHLY twice now (in the past months) -- I have the brush tool. Yet corrosion continues to slowly and evenly build up on the negative terminal. I'm assuming the battery is neither charging properly nor discharging properly and am wondering if this, too, is related.
Remember: This all started after I changed my headlamps months ago and disconnected the battery for one lamp and shuffled the washer reservoir away to access the other headlamp.

 

Perhaps it's a case of "post hoc, ergo propter hoc" (Latin for "after this, therefore because of this")?

In other words, it's something completely unrelated but it's being tied together just because it happened after something else.

 

You definitely have some loose ground that is probably unrelated to this repair. Think back to any work recently done to the truck. Look for grounds, in engine bay and make sure the battery is connected nicely, battery harness clean and polished , use some grease or spray on the battery terminals for better connection too. It's not a reservoir sensor that is a no brainer. . .

Yes, one loose ground can make a car go crazy. It happened on my 2019 Odyssey. . .driving great for 500 miles then BAM shut off on the road with EVERY single light going off.

Towed it back to base. . . Found a loose ground under the seat.

Recruit a friend to help, sometimes a second fresh set of eyes is what's needed.. . My brother found my loose ground after like 15 minutes after I spent a good amount of time.

 

Thanks to taco206 for your response and input. With that issue and this issue, I have definitely considered "post hoc, ergo propter hoc" and thank you for the translation. I'll continue the search for a grounding issue or loose connection of some type. Still, with 218,000 miles (2012), the likelyhood of some failure device seems equally plausible. I'll get to those battery and cable cleaning/brushing tomorrow. I'll pick up some dielectric grease tomorrow. This continues, but thanks to all who responded or will respond.