Truck Shut off while driving (Died on my way to work...)**FIXED**

You're sure not the only one there either.

 

So let's summarize what I do and don't have....

I DO HAVE:
Good Voltage at battery
Good Voltage at engine bay fuse box
Good Voltage going to various fuses and relays in the fuse box
Starter will crank well, but no start
Power to Dash lights

What I DON'T have:
No power to Interior lights (map, center)
No power to Radio
No Power to Scangauge/OBDII port
And of course... no Start

I have checked all fuses, I have not tested (beyond unplugging and replugging in ones I know work) certain relays... but really there shouldn't be many that would cause this issue...

I feel like my biggest clue is that some but not all of my interior electronics are not working... if this was a fuel issue, It shouldn't effect my interior lighting (in my mind..lol)

My next thought is a major short somewhere in my main wiring harness between the engine and interior, and ECU issue or a darn wire gremlin who just likes to watch me suffer. Are there any engine sensors (TPS, Crankshaft Positioning sensor etc) that could cause these symptoms? I know on they can cause no start... but no power in the vehicle?

Good thing it's the weekend and I don't have better things do worry about....

 

I'm assuming (DON"T LISTEN TO ME, I KNOW NOTHING ABOUT WIRING) that you have power into the fuse box but really nothing out of it besides starter.....and I think that's pretty direct wiring. I really don't know if the ECU controls that or not, that's how bad I am with this stuff.

I think I'd start looking at the fuse box and back side of fuse box and start checking for voltage ANYWHERE outside of that.

For instance, power on both sides of fuel pump relay, power to ECU.

Don't forget the ignition switch itself....does jiggling it hard make the interior light flutter?

 

RIP - Wait did you go Jesus on us?

 

I tested 5 or so fuses in the box to see if they were getting power.. as well as all the relays... so that would lead me to believe I've got power leaving the fuse box. Ignition switch... I'll have to play with that...

...BUT... the interior lights are wired separate from the ignition, which is why you can turn you map lights on without a key....

I'm gonna spend a little more time in there... see if the clues pile up

 

Yes... back to haunt TW from beyond... I gotta fix her so I can take my 1st gen to heaven with me and wheel in eternity!

 

He is reborn...

 

I want to be launched into orbit around the sun in my Tacoma when the time comes. I better set up a go fund me page.

 

I've pulled apart the interior fuse block, looked at connections, checking voltages, no luck yet. Somewhere randomly I got power again as my map lights came on... So I tried starting her, she purred up and shut down 5 seconds later... But I did hear an audible click when things shut down. Any specific relays inside that will make this happen?

 

Still at a loss here. Like I said if it were a no start without any another symptoms I'd start looking at sensors(TSP, crank...) but since I've got random power to some things in the truck but not to otheres... It's kinda dumb founding. The one commonality I keep coming to is the kick panel fuse box itself... Are these ever known to fail? What does the inside look like?

I mean all interior power is run through that box including the ECU.... Is it even serviceable?

 

Do you get ANY power in AND out of it?

I'd have to look at one but does say, the interior light wire (I know that's in there) show power on both sides of the fuse?

As stated before these things drive me crazy too but I guess you'll have to track down from 1 direction or another where power is being lost.
If the fuse box under the hood shows power on the back side coming out I guess you're on the right track.

Sure sounds like a relay opening in that it keeps starting, then stalling.

Do we have a main fuse or relay? Old Honda's used to fail regularly with age at that point.

 

I'm not sure what you mean by in and out... I tested every single wire going into the backside of the kick panel fuse box, and there's only one that shows 12.5V and two that are at 3.5... I'll have to pour over the wiring diagrams to determine which wires these are.

I also disconnected the starter (both pos and neg leads to the solenoid) and the ground wire to the engine block to see if I was having a short there... no luck.

I think my next step is going to the ECU to take a look...

 

Everything with a fuse has power coming in (turn on a light and complete a circuit).....fuse.....power going back out to component (lights, horn whatever)


Sometimes (rarely, its a fluke and not in your case because you have so much out) a fuse may LOOK good but you have to probe both sides to make sure power is indeed going through the fuse.

In other words, I;m not thinking you have a fuse out, rather something may not be energizing a whole block of fuses or maybe a relay box.

Something big like an ignition switch that controls so much. In your case, you;re right it shouldn't be that because of interior lights.

The ECU is usually the last thing that would give problems but it's sure not unheard of either. Especially if there's any chance it got wet.

It won't hurt to pull it out of it's bracket and look and probe for power.

 

You need to look hard at your AM2 fuse and positive post on the alternator. The Tacoma has two separate electrical systems effectively, one for under hood and one for in cab. All electrical for in the cab comes from the positive post on your alternator through the AM2 fuse and then into the cab via the ignition switch. If your positive lug is broken/dirty/corroded on the alternator or your fuse is blown or not holding a load, you will have symptoms you are describing. If the alternator and AM2 fuse check out (verify power into the fuse terminal by testing the contacts with a multimeter, one will be hot and the other not) then you probably have burnt ignition switch terminals.

Just had the same issues last week. Ended up being a broken alternator lug. My 80amp alternator fuse blew as well when the post broke and hot leads were flopping around.

 

are you getting fuel? or spark? it can turn the engine, but if no fuel or no spark it wont start....

 

Just checked the AM2 terminal coming off the fuse box... 3.5 v... Everything else shows 12... Did we find a winner?.... Now to figuring out why

 

How do I get to the inside of the box... The wiring harness makes it a bit difficult

 

Take out the 3 10mm bolts holding the whole box down and then pry it apart while pulling the 5 or 6 little tabs out that hold it together. An extra set of hands really helps but you can do it with some patience and cursing.

Sounds like you may have. The hot side of the AM2 terminal goes directly to the alternator post that is then tied to your positive battery post through another cable. Something must have a bad connection in between the positive battery post and the hot side of AM2

 

I’d hold off on opening the fuse box and start from your battery and then work towards the fuse box. Odds are you’ll find the issue near the battery post or the alternator post connections

 

This sounds like good advise especially if you can find 3.5V further out than there.