melted my jumper cables jumping my FJ.. wont jump.. wtf? (1 Viewer)

[wantatlc]

your night switch is on the ground side ? , if so you won't have it light up unless the switch is on or you put it directly on the - terminal .

i think you have a big dead short in your wiring , one of the heaviest gauge wires you have most likely . it is grounding out , rubbed through or something . start at the battery + and work your way down till you find the melted / burned / grounded / wire .

if your night switch was on the + side i would of possibly blamed it but you are usuing it on the - side so there is nothing wrong with it .

yes, kill switch is on the ground side - I always had it that way from the day I installed it. my logic was it is better to disconnect ground first, so it made sense to put disconnect into the neg cable.

I will check the + cable from battery down to the solenoid, but I am pretty sure it is perfect. could it be the solenoid since that is what the biggest power wire is tied to?

if I do not find that fat + wire off the battery too be bad, how do I go from there in finding the "short" - hundreds of feet or wire in a 30+ yr old rig hacked together by numerous owners... how do you even start or process it?

 

[wantatlc]

not until your night switch is turned on .

a digital multi meter will also show polarity , if you hook the leads up backwards you will get - numbers . if you don't have one you can buy a cheap one for like 25$ its a better tool then a test light .

I do have a digital multimeter. I tested the battery at 4.75 volts.. but to be honest, I have 2 degrees and neither taught me how to correctly setup the meter (which dial position to select for what test) so not even really sure how to incorporate that into this process to solve my issue.

 

[DanS HJ-45]

The position of the knob depends on the type of DMM you have. Post pics if you have any.

But basically, you're looking for a VDC reading, with a range of 0-20 probably (anything over 14 is good). VDC will have straight lines, and not squiggly lines (the squiggly lines indicate AC Voltage).

Once you've done that, touch the two leads together. It should read zero. Then, put the ground (usually the black lead, probably marked with a GND or a ground symbol) on the negative side of the battery, and the positive lead on the positive side. You will get a number, which should be about 12V in an ideal world, but the + or - sign (probably just nothing or a minus sign) will denote the polarity. If you have the leads set up correctly, then you get a positive number. If backwards, you get a negative number. That is: assuming you have a good battery. If you want to test it, just try it on a working car, and then compare your cruiser to that. That's the easiest way to make sure the battery didn't switch polarity.

Dan

 

[LAMBCRUSHER]

BIG X2 on the dead short. In the always hot circuit- either the big wire to your starter, or the 10 gg 12 volts to your amp meter/ig. $ (plus 12 to your switch- the first place the circuit goes to, before the switched loads.) Possibly the starter/solenoid are shorted. Check wires first.

 

[Brian in Oregon]

Sure you didn't turn the battery jumper cable leads around?

 

[Pin_Head]

sorry, but how are these different "Disconnect the battery and try jumping it. Also jump to the battery only."?

You remove the battery and try jumping to the cable ends. Then you try jumping to the removed and disconnected battery. One of them will smoke the cables.

 

[wantatlc]

Once you've done that, touch the two leads together. It should read zero. Then, put the ground (usually the black lead, probably marked with a GND or a ground symbol) on the negative side of the battery, and the positive lead on the positive side. You will get a number, which should be about 12V in an ideal world, but the + or - sign (probably just nothing or a minus sign) will denote the polarity. If you have the leads set up correctly, then you get a positive number. If backwards, you get a negative number. That is: assuming you have a good battery. If you want to test it, just try it on a working car, and then compare your cruiser to that. That's the easiest way to make sure the battery didn't switch polarity.

Dan

4.75 on the rig versus 13.5 or so on my car

BIG X2 on the dead short. In the always hot circuit- either the big wire to your starter, or the 10 gg 12 volts to your amp meter/ig. $ (plus 12 to your switch- the first place the circuit goes to, before the switched loads.) Possibly the starter/solenoid are shorted. Check wires first.

wire check monday morning. hoping no bad starter/solenoid - but I guess if it is not an obvious wire issue I can see right off, I will pull it and have it tested with the battery. I just have this suspicion the main larger wires to and from block and 2 and from starter are just fine.

Sure you didn't turn the battery jumper cable leads around?

yep

You remove the battery and try jumping to the cable ends. Then you try jumping to the removed and disconnected battery. One of them will smoke the cables.

likely try this next - after inspect wires first of course. I follow your point. takes each one out of the loop. 1 of them will smoke the cables and I will know. heck, I should not even have to try to actually "jump" anything as currently, just hooking up the jumpers and they smoke - car does not even have to be on.

btw - something I notice - which was never an issue and may not be but that now does not make sense. I have had the kill switch for years - I have a heavy gauge ground wire coming from lower engine block to the kill switch and then from kill switch to battery BUT also another ground wire on the same bolt mount as the one from the engine block goes to an existing bolt on the fender. why would there be 2? I would not have added the second, it would have been there and I bet my original photos show it. so I am sure I just added in the switch and used what was in place, but now that I think about it.. why a ground from the engine block AND another off to the fender??

 

[MoCoNative]

Well, what I see is a drain and short somewhere. The voltage of 4.75 on your cruiser battery says the battery is dead, and jumping it may not start it period, because the dead battery is taking so much juice off the car that none is left to start the cruiser. this high charge rate may be one reason for the smoked cables. In stock form a Cruiser would have had a ground wire from the block, and or the starter bolt to the frame and then a second ground wire from the battery to the frame.

You may still have a bad ground issue, DC systems require power to flow from the positive side of the battery to the negative side of the battery. The starter is the biggest draw of power, or amps on the system. Bad wires, due to corrosion in the wires, or corroded attachments increases the resistance, thus requiring more power, or amps to push the power through. Not having a good ground from the starter or block to the battery requires the power to push through the block, then some bolt, then maybe a bracket, etc, until it finds it's way to the battery. In other words, it's like plumbing. A straight run of big pipe will flow more, than a crooked clogged up and even broken pipe.

The second ground wire to the fender doesn't do much I would guess, but you do need to ground the frame of the rig and the engine block back to the battery. All of the lights, heater blower, guages and stuff ground the body. they rely on the steel of the body to carry the negative current to the frame and then to the battery. Newer Toyotas began running dedicated ground wires all over to get better energy flow without relying on rusted body mount bolst and such to carry the load.

I had trouble with grounds, ended up running everything to one point and then to the battery just to be sure.

My theory, is you had something drawing power and draining the battery the last time you drove it. The rig will run off the alternator, especially if you are not running lights and stuff, pretty much forever, even if the battery is dead. So your battery may have been dead when you stopped it last, but it will not restart, as you have noticed.

Try like pinhead said, take the leads loose and see if it will jump with the battery out of the equation. Check your grounds and battery cable. Elimate any shorts or drains, and just go trade the battery in for a new one, if you can get a good warranty deal. I've never had much luck getting even a good new battery to work well again after it discharged all the way down. Sometimes it just ruins them.

 

[Bossman]

You didn't say anything about having one but if you have an electric winch you will want to isolate that as well for testing purposes. I'm betting bad cable to the starter or bad starter. If the cable is good I would take the starter off and take it to a shop to have it's condition checked.

 

[edwjmcgrath]

Chech the optima site for recharging a dead battery. They require a different procedure from normal batteries. You will need another battery to parallel the dead one.

 

[wantatlc]

You remove the battery and try jumping to the cable ends. Then you try jumping to the removed and disconnected battery. One of them will smoke the cables.

You have some kind or short; either the battery or the truck. Disconnect the battery and try jumping it. Also jump to the battery only. that way you will know whether the short is in your truck wiring or the battery. When you connect to the truck with everything turned off, there should be no sparks.

okay... here is what I found

car battery hooked up to FJ battery that is wired up as it would be normally = sparks & melt

car battery hooked up to FJ battery that is NOT wired up (removed + and - wires so they are out of loop) = no sparks or melting

car battery hooked up direct to FJ + and - wires (so battery is out of loop) = sparks & melt

I did not try to jump, just made connections.

thoughts?

 

[edwjmcgrath]

If when you say "sparks" you mean serious sparks and melting wires, it sounds like you've eliminated the battery and any shorts in the FJ that are independent of the ignition switch.
If the car is wired correctly, everything else except the starter should be fused.
I would suspect a short in the starter or possibly a short between the + cable and the frame that went away when you took the cable off the battery.

I wouid inspect the + battery cable carefully for worn insulation, then I would try to start the car.

 

[Pin_Head]

You have a big time short somewhere in the high current side of your chassis wiring. Check wires to the starter for obvious shorts. If good, start disconnecting stuff and check again. Disconnect the wire to the B+ post of the alternator, the battery cable to the starter, the fusible link at the battery cable + post, etc until you find the short.

 

[wantatlc]

checked main gauge - wires from engine block to kill switch and kill switch to frame and kill switch to battery. all fine.

checked main gauge + wire from battery to the starter. all fine.

cleaned all connections for all of them.

it seems the first thing I need to do is to get a fresh working battery, no?

 

[edwjmcgrath]

Sorry, I misread your post. You only eliminated your battery as the cause. Don't try to start it.
You have a big short somewhere in the + side. If you are melting jumper cables then I would be looking at big wires. Starter, between battery and fusible link, or possibly the alternator B+. As pinhead says, just start disconnecting.

 

[edwjmcgrath]

it seems the first thing I need to do is to get a fresh working battery, no?

I thought that you said that when you hook another battery (in a different vehicle) to the +/- cables in your FJ, it sparks and melts.

If that's the case, the problem is in your wiring, not your battery.

That said, before you toss your optima you should google charging an Optima. You will need to use another battery and a high output charger.

 

[wantatlc]

Sorry, I misread your post. You only eliminated your battery as the cause. Don't try to start it.
You have a big short somewhere in the + side. If you are melting jumper cables then I would be looking at big wires. Starter, between battery and fusible link, or possibly the alternator B+. As pinhead says, just start disconnecting.

having a hard time doing this correct & not sure what more to remove/do - not sure what a "fusible link" is? But, I checked the wire between starter and battery, it is perfect and touches nothing. I have several power wires for various extras that connect to the + pole clamp, I removed all of those. I pulled the wire that runs from main post on the alternator (B+ I believe you call it) - FWIW tracing that power wire it goes from the alternator into the firewall (I did not go farther) and you guys make it sound like it should go direct to the battery? anyway, still with that when I use jumpers and hook the car battery to the FJ + cable and touch the - cable (with battery pulled out) I still get sparks??

(see image of the alternator setup)

I thought that you said that when you hook another battery (in a different vehicle) to the +/- cables in your FJ, it sparks and melts.

as per above.. that is the issue.

The reason I say get a new battery is it is under warranty and Costco will allow me to swap it. so, in 1 month my warranty is up, so why not swap it as clearly I do not have a second battery nor charging unit to try to bring this one back to life?

what the heck and how all of the sudden is this possible. ugh! only new thing in months is the starter/solenoid - now this.

 

[NikP]

Remove the positive terminal from your starter, make the the cable doesn't touch anything while you then hook up a battery as you normally do. If no sparks or melting then you've isolated it to your starter, otherwise if you get the same results it's in the circuitry of the key.

 

[edwjmcgrath]

Hey, if the battery is free, go for it. You still have to find your short though.

Fusible link is like a fuse. The ammeter connects to the battery through it. The other side of the ammeter goes to the B+ of the alternator and the fuse box. Basically, that whole section of wires is high current and only protected by the fusible link.

I would next try disconnecting the battery cable at the starter and see if the shorting goes away. If it does then you've found your culprit. If not, the next step is to find and disconnect the fusible link.

 

[wantatlc]

Remove the positive terminal from your starter, make the the cable doesn't touch anything while you then hook up a battery as you normally do. If no sparks or melting then you've isolated it to your starter, otherwise if you get the same results it's in the circuitry of the key.

if you remove the starter from this, disconnect it, then the issue MUST stop no since the + cable then goes to.... nothing... so what would that prove? that would not prove it is the starter, no?

"circuitry of the key." - that is a first mention of that