just did a test drive today and found the white large power wire burning and melting. the wire is right at the alternator.


why is it melting right there?
is it because the alternator is going bad or is it because something is grounding?

i was starting to think it was because of something in the car is grounding but nothing new is installed recently.
also if something is shorting in the car would the wire melt at the battery, being that the wires are all fused but at the battery and not directly at the alternator.

any help is appreciated.

 

The WHT wire leads to the battery. I suspect that the wire insulation was damaged, causing the wire to short out somewhere near the alternator. You need to cover all exposed wire with electrical tape to prevent additional electrical shorting.

 

do you think the alternator is damaged?

could there anything else be damaged as well?

is there a test i can do to test out the other wires?

 

What year Civic?

First repair any exposed wire. Then, test WHT wire (6th generation Civic):

Disconnect the alternator connector and remove fuses 39 and 41. With one probe of a multimeter (set to measure resistance/Ohms) touching the WHT wire terminal of the connector and the other touching a metallic part of the body frame, you should get a very high (infinite) Ohm reading. If not, the WHT wire is grounded somewhere and needs additional repair.

 

its a 91 civic.
i assume those are not the fuse i want to take off.

dumb question, as i have never done this before.
do i leave the other end of the white wire on the battery?

 

The two fuses to remove should be #31 and #32 for a 91 Civic. Removing these fuses serves in essence to disconnect the WHT wire at the battery. Also check whether either of these two fuses is blown.

 

another thing to check is your battery terminal. check that white wire on the battery terminal. it could have a badly coroded terminal as well. take that side wire off the battery terminal and clean the main terminal and the wires ring terminal really good with a steel wire brush or what not and reinstal. best to add some electrical grease but most people dont have that in there tool boxes the simple test is clean the terminals reinstal everything and then start your car up and put you hand back there where its melted alittle alraedy and simply feel for any heat building up. that white wire goes directly to the battery so if it was shorted out your whole car would be a fireball right now! typicaly its just a bad terminal or your alternators internal regulator has gone screwie and puting out to much charge. youd have to drive the car up to a autoparts store that can test the alternator on the car to check that out really.

and if the problem still remains from melting the wire than i would sugest geting some 4gauge wire, some ring terminals and make a new alternator charging wire! just run the wire from the battery where the old white wire was connected to the alternator where its conected, use some wire loom over the wire to prevent it from wearing thru, and zip tie the wires clear from any moving or hot parts. i zip tied mine on the brake lines on the firewall in several spots when i upgraded my charging wire. but im still using both wires since i have a upgraded alternator. but if yours is stock and a good alternator then just take that wire off and tape over the terminals on both ends and tie them up outta the way of anything. i wouldnt cut them off. just unhook them. ya dont want to hack up the harness, but since the wire is already melted definatly just unhook it on both ends just incase it might have melted into another harness wire you wont have any feedback if that wire touches the block or what not.

 

thanks. im very curious if anything else like wires in the car are melted?

should i put an inline fuse on the charging wire?

i was thinking of just taking out the white wire at this point. it might serve as to see if it messed up any other wires around it in the harness, plus i plan on just installing a new recharging wire since this one is obviously melted.

i do have the ability to remove the alternator to get it checked out again. since i did it at kragen i wonder if their test machine is any good?

now im also curious if this is what is causing my call to idle like a roller coaster for the past month and the stall outs too.

 

well they should be able to test your alternator out with it on the car if you just drive it up there....

you could put a inline fuse on the alternator wire, just be sure its around 100amps. stock alternator puts out i believe around 70-80amps. a car stereo inline fuse about 80-100amps should be good for the new charging wire.
tho to check the old wire youd really have to pull the motor because that wire is ran thru some engine harness wires and under the intake manifold which is a huge PITA by itself.... so i would just tape the ends of that wire up and leave it disconted on both ends.

 

I also think that testing the alternator would be a good idea.

The fuses that I mentioned serve to protect the alternator circuit, so it would be unnecessary to add an inline fuse on the WHT wire. That's why I asked whether either of those fuses was blown.

How extensive is the damage on the WHT wire? If the damage is localized to a small segment, you could probably just repair it.

By the way, a bad alternator/WHT wire could cause an engine idle/running problem.