98 Toyota Camry MELTDOWN!

Ok not completely. However, the alternator cable on the top of the alternator has completely burned through! The plastic cover started smoking after my battery light came on, so I popped the hood and, there it was crispy as toast. Battery seems good, 12.4 volts when I checked it alone with multimeter. Also took alternator in to auto parts store to check it, they said alternator was fine! Thought maybe it was a short, but it burned right there next to connector on alternator. I am puzzled, but I am sure you all can help me out. Thanks. I also attached a picture.

You probably have a bad connection, not a short circuit. If the connection is bad, it develops a small amount of resistance to the current flow. The current flow then produces heat at the connection which makes it worse. The end result is what you have observed.

Try replacing the burnt cable and clean the connection point on the alternator. Everything should be clean and shiny.

The evidence to what happened is just to the right of the terminal and nut. Something metal (wrench?) dropped on the terminal and housing and shorted out. When you stopped…the object fell onto the top of the engine or down on the pavement. Look around for it. It will have burn marks just like the housing. The housing should not have a long straight weld mark on it. BTW…I was a missile and aircraft inspector for many years. The photo is a dead giveaway.

I agree with markmast. A similar thing happened to my 1984 Cavalier. A warning light came on. I looked under the hood and saw that the ground wire from the alternator to the body had broken. (On that car the alternator was up front and high, very accessible, and the ground wire attached to the body near the top of the radiator.) Reattached it then and there, later crimped on a new connector, and the car went to its 207,000 mile trade-in time with no further charging system problems.

thank you markmast, missileman and shanonia for your help, i appreciate your feedback. i was just wondering how to replace that section of wire? it seems compromised at least two or three inches from the connection point. I don’t think i can cut and stretch. thanks again for your help guys.

Do not try to reuse the cable, buy a new one. There may be corrosion inside the cable which is adding to the internal resistance. Check all the battery cables while you are at it, if they are original from 98, time to think about replacing them also

Very corroded. Corrosion causes heat and more corrosion. Clean all connections with a wire brush and replace the wires.

Replace the cable and I’m pretty sure that this cable is the fusible link. You will have to purchase a new fusible link. It should run from that terminal to the battery.

I also agree with @Missleman that something was left under the hood and that is what shorted the cable out.

By the way I’m missing a 19mm 1/2 inch drive impact socket. Maybe it’s mine???


I had this happen on a Cavalier I once owned. The crimp on the lug just deteriorated with age. In my case it wasn’t a case of a tool causing a short. There was a heavy rubber boot insulating the lug. I ended up having to buy a new lug a Home Depot in their electrical dept. The lugs at Advance Auto were not nearly heavy enough. I had to patch in about 5 inches of wire. Making a good splice was the tricky part. The fix lasted the life of the car.

Are we not looking at a failed ground strap?

The alternator gets it’s ground via the mounting bolts. That’s the B+ terminal.

Check. Sure is heavy duty!

thanks for all your help guys, did a temporary fix, cut off burnt end and cleaned connector up, then reconnected it to alt. runs good now, (no batt indicator light) but the wire still gets too hot, ( not burning). wrapped it in electrical tape, tape seems already stiff but not melted. i think i vaguely remember i might have left a wrench there a long time ago, realized it then took it off after it arced and i shut off engine. that probably started the higher resistance problem til it finally burned up. def going to replace that wire though, still cant tell exactly where it goes. it intersects another wiring harness, guess maybe i should get a diagram. Yosemite says it goes to the bsttery from that terminal, but from what i can see, it doesnt look like a straight shot. sorry guys, electrical not my strong point, well really nothing on cars is

Just some food for thought, but maybe the battery is not as good as thought. The fact that your multimeter shows 12.4 volts does not necessarily mean the battery is good.

Just wondering if the battery has an internal fault which is causing the alternator to struggle and work overtime so to speak…

Connect your multimeter and see what the voltage does while the engine is being cranked over.

I might also ask if the battery is maintenance free or if it has removeable caps for the addition of water if needed. With the caps removed you can use the multimeter probes to check each cell by probing 2 adjacent cells at a time while moving down the row of filler holes.
You should get a roughly 2.1 volt reading at each stage.

I would still replace the whole wire. If we’re talking the wire that charges the battery from the alternator, and not one of the skinnier wires, this wire is rated to take the full output of the alternator. If it is heating up, there is unwanted resistance somewhere. Either your splice isn’t as good as you thought, or water may have intruded and wicked up under the insulation, causing unseen corrosion. Maybe disconnect the wire and check the resistance with an ohmmeter. Also, if you have a clamp-on amp probe, check how much current is flowing through the wire when it gets hot.

Finally, you could have a good battery and alternator, but there may be a hefty current drain elsewhere, such that the alternator is struggling at full capacity to keep the battery charged even with few accessories operating. If your voltage at idle is not at least 13.5 volts with no accessories on, I’d suspect a problem. Maybe also feel the fuses in the fusebox when the car has been running for a bit–none should be overly hot. Sometimes you get a situation where a fuse won’t blow, but it will get hot enough to actually melt a bit.