My Grounds Are Burning UP

As it says when I start my (( 2,7 occasioally the grounds smoke and burn. If i put my headlights on it will burn up my alternator.. Right now Im replacing ground wires but I need some answers for an amature. I dont know how to work a electric scanner. Is the ignition switch on Tacomas been known to short out. The problem seems to be at start

 

The grounds burn up?

 

I’ve seen this before (on boats), and the problem is generally the main ground is broken or corroded so that it’s a higher resistance than a smaller ground, and electricity finds the easiest path to ground, through something it isn’t supposed to

I’ve seen small ground straps glow red from the current going through them. Fix it before you start a fire

 

Have you changed anything recently related to the electrical system? Lights? LEDs? Switches? New alternator? Battery change? Fuse box mods?

If anything has been added or modified recently, I'd start there.

 

When your ignition switch goes bad.....normally it blows the AM1 or AM2 fuse, or both
or stops working

when a main common/ground in a house breaker box is broken......it causes the appliances in it burn up one by one...looking for a ground


You should have a heavy duty ground going straight to the block
that can get rusty/corrode down by the motor mount


As these age weak grounds and vac leaks begin to plague these

 

I just put on two much stronger ground straps...I will work on it more tomorrow. It starts and runs great most of the time but my key switch seems old and sloppy. On my old Mustang the key could be responsible for the car burning up

 

Your key cylinder should be replaced every 150K.....
if you wait too late.....key may not come out and you have to drill it out to get it all apart.

I'd also recommend replacing the back switch part every 150K.....
that can put you walking when it goes out


beats all sheeet.....nothin lasts forever.....some of your existing faith is driving on bald tires

 

It's bad ground day is Venus in retrograde?

 

I’m way over due, almost 500k but still work fine

 

12V under high amps will find a ground even if it's a weak one. Corrosion isn't very conductive.

 

The truck seems to smoke the ground wires when I turn the key. On my old mustang its a problem in the steering column

 

There are 3 grounds in the engine compartment that you need to investigate, one from the battery negative to the engine block, battery negative to the innder fender and p/s cylinder head (V6) to firewall. If you dont address this the current WILL find a way back to the battery usually through the throttle cable or the TV cable if an automatic.

 

As stated I'd clean and reseat all your grounds.....

then I'd look for a stuck relay......I'd be attempted to pull em all 'cept for the efi and starter


With the key on and engine off......what does an amp probe say

 

That is when the AMPs go big. One of your major grounds isn't grounded so the electricity is finding an alternative route over thinner wires. And like glamisman said it can even run through a throttle cable and ruin it by melting the liner.

 

Great help guys...I replaced the two smaller ones with large wire. tomorrow I will go after the main one off the cyl. head. I will respond how it worked