Need your help guys! Battery shorting problem.

[AlphaQup]

Been MIA for a minute. Now I need your help folks.

Long story short, I have a 2006 4runner V6.

Can a bad starter or alternator cause your system to short and fry the battery?

Car started fine this morning. Earlier when I tried to unlock my car with key fob it wouldn't unlock. Found the battery dead and super hot to the touch. I tried jumping the car but all I got was clicking from the starter and none of my lights are working except the map and trunk lights. AC and radio are dead as well.

When I try connecting it with a good battery the connecting cables get so hot they start smoking.

What do you guys think the problem is?

Thanks!

 

[wcjeep]

Starter would be easiest to check. It's possible for a starter to have severely worn contacts. The plunger could become wedged between the contacts. Not a common fail. I would completely disconnect the battery cables. Test from Positive cable to ground with a multimeter. What is the resistance? Should be more than Zero ohms. Next, disconnect the positive cable at the starter. Retest resistance at the battery Positive lead.

 

[AlphaQup]

Starter would be easiest to check. It's possible for a starter to have severely worn contacts. The plunger could become wedged between the contacts. Not a common fail. I would completely disconnect the battery cables. Test from Positive cable to ground with a multimeter. What is the resistance? Should be more than Zero ohms. Next, disconnect the positive cable at the starter. Retest resistance at the battery Positive lead.

I removed the battery line to the starter and connected a good battery. It's still shorting/cable heating up. This means it's the alternator that could be bad instead right?

 

[Bumbo]

Sounds like you have a pretty substantial issue if your mains cabling is getting hot enough to start smoking. I would expect to find some permanent damage that needs to be corrected. For example, if the insulator melted and is laying on the frame or some bolts, you have direct short to ground.

As soon as you found the battery very hot to the touch I would have disconnected any power sources and probed around with only a multi-meter because it takes a massive short (internal or external) to get a battery to do that.

Trying to jump it or attaching another healthy cell in parallel isn't without risk either. Throwing more current into the system would have only added to the existing damage.

Do you have any electrical modifications? Car stereo, dual battery setup?

I would check resistance between the neg and pos battery posts with the battery disconnected and start there.

 

[AlphaQup]

Sounds like you have a pretty substantial issue if your mains cabling is getting hot enough to start smoking. I would expect to find some permanent damage that needs to be corrected. For example, if the insulator melted and is laying on the frame or some bolts, you have direct short to ground.

As soon as you found the battery very hot to the touch I would have disconnected any power sources and probed around with only a multi-meter because it takes a massive short (internal or external) to get a battery to do that.

Trying to jump it or attaching another healthy cell in parallel isn't without risk either. Throwing more current into the system would have only added to the existing damage.

Do you have any electrical modifications? Car stereo, dual battery setup?

I would check resistance between the neg and pos battery posts with the battery disconnected and start there.

Going to grab me a multimeter and check.

Only mod I've done with this truck is the VSC mod that everyone else on this site does. I have been driving around with it engaged for the past few days. Could that have caused all this?

 

[keakar]

ya it sounds like the alternator is shorted out.

check main lug or main wire to alternator to ground and i bet you have little to no resistance showing its shorted to ground

also however, that main wire to alternator might have melted to the exhaust manifold and shorted out that way

 

[visualfxengineer]

If it’s smoking at the cables, I would say short. Only times I smoked heavy wires was too close to the headers and a short at the starter.


Sent from my iPhone using Tapatalk

 

[AlphaQup]

ya it sounds like the alternator is shorted out.

check main lug or main wire to alternator to ground and i bet you have little to no resistance showing its shorted to ground

also however, that main wire to alternator might have melted to the exhaust manifold and shorted out that way

I'll check it tomorrow. Thanks man.

 

[AlphaQup]

ya it sounds like the alternator is shorted out.

check main lug or main wire to alternator to ground and i bet you have little to no resistance showing its shorted to ground

also however, that main wire to alternator might have melted to the exhaust manifold and shorted out that way

I unplugged and took the power cable off the starter and it's still shorting.

 

[wcjeep]

Stop connecting a battery to check for a short. Use a multimeter. You could cause a fire. Obliterate the computer. Any number of bad things. Use a meter. Grab a friend to help. Flat bed the vehicle to a mechanic. Do not connect a battery for testing.


Battery positive to alternator is disconnected. Cable to battery positive is also disconnected. Start checking ohms resistance from positive cable to ground. Are there fusible links not melting as designed? Did something get hot? Check every inch of the positive cable. Weird it's not blowing/melting something.

Do not hook up the battery as a test method.

 

[keakar]

I unplugged and took the power cable off the starter and it's still shorting.

im going to assume you meant the wire to the alternator

if you disconnected the cable from battery to alternator and the battery is still shorting out, then next disconnect wire to the fuse box from the battery and see if its shorted to ground. just keep following things until you separate it to the point of isolating what is the item that is shorted to ground

as wcjeep mentioned you should be testing for short to ground using a multi meter and not battery power looking for sparks or wires getting hot

 

[mikedbom]

This issue sounds a lot like the one i'm having now. only voltage checks i have performed are on the battery...will do the shorting checks now. Would a shorted alternator cause the issues the OP was having? I tried to jump my truck just now and the battery wouldnt go over 10V. Kept smelling burning something and used a temp gun...found the alternator was close to 300F!!! Any advice would be appreciated and i was hoping there was a solution from the OP here...4 years later lol.

 

[mikedbom]

just wanted to close my comment...replaced the alternator, got the battery good and charged and everything has been rock solid since. alternator change out was a piece of cake.