07 tacoma won't start

have not checked the codes yet, had a cel on before I started the swap,the immobilizer blinks yes, all the dash lights come on as they previously before this problem arised. it seems as the battery wont take a charge, the starter does not click but I can hear the solenoid. I will have to check all relays and fuses tomorrow. the last similar problem I had turned out to be the starter, but that was replaced almost a year ago.im getting ticked, I know I screwed up not unhooking the battery, I just wanna drive this damn rig lol.

 

how can I check my ECU?

 

I hope your ECU is fine but this makes sense to me.

 

I'm a Deere mechanic so I don't know the specifics of testing a Toyota ECU, but I bet Bamatoy1997 could help if you PM'd him.

 

Try to pull codes, scanner probably won't connect if the ECU is junk.

If you hear the starter relay click it could still be something hing else.

 

Update so far, all fuses n fusible links are ok. Battery holds a charge. Waitin on a buddy to come by with his OBD2. Come to think of it, I guess it could be the starter before I did the swap I snapped a cv axle n ended up a long night in the river, but it started enough to get into the garage. Hmmmm

 

scanner did not pull any codes thinking its due to the fact that I disconnected the battery. gonna pull the starter tomorrow and have it tested, its got a lifetime warranty advance auto crap parts. if the ecu was bad, the fuel pump would not kick on?? which I can hear when I turn the key. is that correct or no.

 

The fuel pump is submerged in the tank. You hear the ABS pump I'd guess. I welded all of the stuff to my truck with the battery connected, I doubt it's the ECU. They are pretty bulletproof. Try to jump the starter solenoid and see if the starter spins. Check all your frame grounds too if you haven't. If you see any corrosion clean it to bare metal and reconnect. Here are the schematics. Pretty easy to see if the starter solenoid is getting juice with a test light, if it is getting power and the starter won't turn you know it's the starter. If it's not getting power with someone turning the key to the start position, start tracing the circuit back till you find the problem.
http://www.customtacos.com/tech.old...6toyewd/06toypdf/ewd/2006/tacoma/h/em01d0.pdf

http://www.customtacos.com/tech.old...6toyewd/06toypdf/ewd/2006/tacoma/h/em01d1.pdf

 

Thank you, I am going to pull the starter after work.

 

Pulled the starter, noticed a good crack above the solenoid, brought it to the parts store to honor they're warrantee, part won't be in til today. Get my driveshaft back from the shop and new calipers today will post back when the starter comes. Hopin that's the only thing

 

The alternator is grounded to the engine by the bolts that hold it on. Hate to say this but you run a real good risk of having trashed some electronic components with the arc welder. But first things first starting with the battery and moving beyond that. Even old cars and trucks with no electronics can be damaged by arc welding with their batteries hooked up.

 

BS. I have welded to dozens of vehicles with the battery hooked up and never had a problem. Electricity is magic to some people, but it shouldn't be.

 

Thanks everyone! I just replaced the starter and she's running good. My sas should be alive this weekend.

 

Glad it worked out! Post up pics of the completed project when you're done!

 

You have been lucky. One thing electronics do not like is reverse voltage. A welder of any type has voltage way in excess of battery voltage. It is not magic to me I delt with it for many years. More often than not you'll get away with it lot of welders have for many years but there will be day you won't. lightning strikes a tree a hundred feet away and trashes your TV or microwave how did that happen? Yep reverse voltage.

 

All of my welds are done with a DC readywelder running reverse ground for flux core wire. I have at least 20 pounds of wire melted to my truck with the battery hooked up. Lightning occasionally does some odd things, but the difference in potential is several orders of magnitude different than with a typical welder. I'm a radar and radio tech and see the results of lightning strikes on electronics every storm we get first hand. It's not magic, it's just energy looking for the path of least resistance. Unless that path of least resistance is through the printed circuit board of your ECU, it's safe.

 

Once the the ground voltage exceeds the forward voltage all bets are off. In theory this should not happen welding but it can.

 

So you do believe in magic.

 

x2

The nifty little diagram shown previously is indeed correct (considering it is hole theory / negative electron flow current as shown). But it is missing a the connections to a high amperage low voltage current generator (i.e. welder).

Typical welder voltage exceeds the vehicle voltage and the there is enough current to weld/cut the car in half with, never mind reducing a low amp/voltage circuit card to a wet puddle.

I agree that it 'May" not fry the vehicle electronics - but you'd never get near my vehicle.

To some, a little bit if knowledge is a very dangerous thing - especially when they choose to empress it on others ....

JMHO

 

Hey, safety third and all that, feel free to disco the batt when welding to your rig. Riddle me this batman, why does every exhaust shop in the world weld on exhaust with everything connected? How about mobile welding trucks with the ground clamp hooked to the chassis. They weld stuff on the metal bench with the truck running! Being an Army dude I'm sure you've seen the nifty Army issue welders that plug into the 24V slave receptacles... (btw, they wouldn't work if the batteries were disco'd). Go to your maintenance shop and look at how the metal shop has their truck set up. Welder grounded to chassis, weld table mounted right on the bed. I used to work in a Fab shop cutting semi's frames down and installing water tanks. 10 trucks a day, cut in half, welded back together and fish plated...with the batteries still connected. They all still started. Finally, even if the battery is unhooked for safety, aren't all of the ECU's grounded directly to the chassis anyway? Wouldn't the magical electron gremlins creep in through the ground cables?