All electrics dead, then back to normal after a few minutes

2010 2wd Tacoma, 2.7l 2TR-FE, manual. For two mornings in a row, truck will not start. No crank, and lose all electrical power in cabin. After leaving truck to sit for a minute or two, power returns and I can try again. On one occasion it started, on another, it was a repeat of the above for two more times before starting. I have not done any recent electrical mods and I have literally done nothing between when it doesn't start to when it does, outside of waiting for a couple of minutes. This happened on Tuesday morning (after the long weekend, truck was last driven on Friday) and Wednesday morning at around 8am (truck was last started on Tuesday night around 9:30pm). Truck runs normally after that.

I have checked that:
- battery is good (voltage was at 12.45 or higher on both days)
- battery connections are secure
- fuses are secure and not burnt

I haven't checked that all grounds are good (outside of anything I added a while ago or ground wires I can easily see, which are all secure).

The radio retains its presets and the trip meters do not reset. Only thing that resets (to my knowledge at this point) is the clock. I was thinking about swapping the starter relay with another working relay (like the horn relay) but there's no way to tell if it worked because I switched it or it worked because it worked. Any ideas?

 

Remove and clean the battery terminals and posts. Make sure they are corrosion free and tight.

Check the voltage at the battery when attempting to start.

 

U mention No RECENT mods

11/12 year old taco has some modz………………………………..disconnect & isolate OEM harness

check all regular OEM grounds

 

Terminals clean and tight, voltage prior to start is good.

There are mods, but no issues since last changes/adds that tapped into electrical that were done a number of months ago. I did check all the work I did previously and everything looks good and locked down, so not sure where it is coming from. If the problem persists I'll chase it down over the weekend.

 

He means voltage during cranking. If it drops below 10.0 the battery is weak.

Sometimes when testing a battery I'll disable spark or fuel and crank it for a good 6-8 secs just to see if the voltage drops off

 

Check all your bolts and screws in the fusebox, if one is loose it can cause problems. Haven't had a taco problem like that but it happened in my accord, lost buss power to multiple circuits and it would be intermittent.

 

Just because the battery terminals look clean and feel tight doesn’t necessarily mean they don’t need cleaning. I’ve seen many that look good and feel tight but when you unbolt and disconnect the terminals, the posts will be oxidized. Use a battery brush, make the posts silver, brush the terminals.

 

I had this problem a few months back, I basically had to clean the posts due to oxidation powder growing on the terminals and I also fixed the connections from other mods to the battery and *knock on wood* have not had any problem with it since. Just wire brush the battery posts and use a deoxidizer blend of chemicals and water to scrub the metal.

 

I would suggest dielectric grease on your terminals.

 

I’ve seen people use grease to cover the battery terminals to prevent the formation of acid. I’ve found it looks like it works but accelerates oxidation forming on the posts. Battery terminal protector works good. I think the felt pads work even better.

If the terminals have stuck on acid, wet baking soda works good. Dunking it in a cup of coke cola really gets them clean.

 

Dielectric grease is for waterproof electrical connections not for improvement of connectivity. For improvement of electrical connections you may want to try carbon conductive grease.

 

I know what it’s for. But if he’s got corrosion on a connection it will help prevent in the future.

 

If it doesn't crank it's a little hard to check the cranking voltage.

 

I used to use motorcycle chain lube to cover my terminals. It's oily, super sticky so it doesn't fling off the chain. I switched to a spray on battery protector.

I put these on the taco, they seem to be doing what they're supposed to do.

$5 NOCO NCP2 MC303 Oil-Based Battery Terminal Protectors, Anti-Corrosion Washers, and Battery Corrosion Pads (Pack of 2)

https://www.amazon.com/NOCO-MC303S-...&keywords=Noco+felt+pad&qid=1625785059&sr=8-1

For cleaning this works good.

$14 EZRED Cleaning

https://www.amazon.com/Z-Red-S501-B...rds=ezred+battery+brush&qid=1625784934&sr=8-2

These work better.

$14 E-Z Red (505BTSSHQD) Battery Brush

https://www.amazon.com/gp/product/B00I3GNM62?ie=UTF8

$14 EZ Red EZR-BK534QD 0.75 in. Power Drill Wire Brush

https://www.amazon.com/gp/product/B07FJN51J9?ie=UTF8

 

2 people and a wiggle test.
That’s all I can add to this.

1 in the truck.
1 outside wiggling wires.

If that doesn’t work. You’re going to need to break out the test equipment.