found alternator wire melting?

949

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.

ragenasian

How much voltage is your alt putting out? The cable could be bad resulting in too much resistance. Also check your grounds and make sure they are good. Our cars are old and the grounds might look good but can be in need of being cleaned up.

949

I have not checked the volts yet. which grounds should I check first?

I only know of 2 or 3 grounds in the engine area.

949

when i check the volts what am i look for?

ragenasian

With the car running you should see around 14 volts at the battery and at the alternator. If you have 14 at the alt and a lower number at the battery your cable could be bad. This will also let you know if your alternator is in good shape. The only times I have heard of that main cable getting hot was from a short in the electrical system, grounds, alternator being bad, or that main cable being bad.

I am no expert so I could be wrong

949

checked it out today. the bolt holding the white wire was very loose. i tighten it back up just to see and its working again.

when i checked the volts i never saw 14v. i only got as high as about 13.6 while driving it fast.

is it something i need to change out?

ragenasian

Did it fix your wire problem?

13.6 I wouldn't worry about. From what I have read alternators should produce around 13.5 to 14.5 so I wouldn't worry that is if you aren't having any starting issues.

The shops like Autozone can test your alternator for you also just to make sure.

949

i looked at it yesterday. in fact the bolt holding the wire was very loose. it was about to come off.

i thought i would just tighted it down and take a drive first before i do anything else.

well it seemed to help the power failer issue as the memory in the cars radio and such is much more stabilized.
so i guess ill just leave it for now, if it acts up again ill do more.

the idle on the other hand is still present. the symptoms have changed a little bit. it does not bounce as much. it just stalls out a lot when i let go of the gas now. start or warm ups are ok, very good idle during warm up. its just happens only if i give it a tad bit of gas. it just drops down and stalls out. i can make it stay at idle only if i let go of the gas pedal slowly. then it stay at about 750-900 rpm.

i just cant figure it out.

if i only knew enough about which parts do what and gives me this reaction i can then test that part out.

so far i have
clean aicv,
tested aicv to see if plunger moves when pluged up,
it moves,
new o rings on aicv.
cleaned fitv,
new o rings on fitv,
clean t/b
clean intake manifold,
new intake manifold gasket,
new tps sensor,
calibrated sensor .45 volts,
new pcv valve,
new fuel filter.

these are my new guesses:

i have a bad alternator,
i have a bad distributor,
if i know how to test a distributor that would help,
aicv is actually bad,
there is a leak but i still have not found it.

Kahuna

Check your alternator for AC current coming out of it..

Anything over .5 AC volts is too much. If you are getting more than that there is something in your alternator failing..

You should be getting 12.4-12.6 DC volts when the car is off, and 14.2-14.6 DC Volts when the alternator is running...

Undercharging issues:
Battery-
Power or Ground Problem
Bad alternator
corroded or damaged battery cables
Bad voltage regulator
Abnormally high electrical demand
Loose or Slipping belt

Lucky for you I am studying charging systems at school right now..

949

thanks for the heads up.


i just replaced the alternator. no change what so ever.

i got the alternator tested and they say its actually still very good. so no internal damage to the alternator.

NZ-DB8R

If the bolt holding the wire onto the alternator was loose then it was causing arcing when a load was drawn, this would have caused the cable to heat up and cause your melting problem

evol911

Do you get a whistling sound when you drive? Could be the idle screw on the TB is adjusted wrong. When you first start your car up the ecu is in a different mode than when its warm (thats why there is 2 different rev limits in the ecu, one for cold operation and one for warm or operating temperature) so most sensors aren't being used until you get to operating temp and the idle is pretty much determined by the temp of your coolant until the motor is warm. There is a coolant line that runs through your throttle body to warm the air coming in to the motor, (tip: bypass the throttle body with the coolant lines and run cooler air into the motor) then goes to your IACV, now when there is air in these lines the bubbles will usually accumalate at the Idle Air Control Valve and screw with it pretty bad. Thats why you get up and down idle because air is bouncing back and forth in there making the car think its cold then warm then cold and so on. Wish I could help you hands on, I think I could most likely troubleshoot it in no time. Text doesn't get the full scope of the problem across.

949

yup i agree. i sure wish you were here. i just cant seem to figure out the problem. its been so long that i dont know what else to try .

i was also told that the ecu might be bad.

so i guess the only thing i need to try is to change out the ecu and see what happens.

Kahuna

Or you could bypass it like he said.

All you have to do is get a 3/8" (i think) hose and run from the outlet to the other outlet.

I do it when I replace my intakes..

Also,
I had a shop owner look up electrical diagrahms for a integra (my engine specs) and he said it looks like the alternator is case grounded to the engine.. This is probably the same as the d-series..

Was your new alternator painted? That could cause bad grounds..

I suggest sanding all your grounds down to bare metal, then re-attatch them, then cover them in clear silicone to prevent corrosion..

I just ran a wire from my alt case to my chassis and now I am charging correctly, as before I was getting 27 volts of AC current, and only 12 volts of charging power.

(I am having charging issues as well)

949

i think the wire is ok for now. i do think my ecu is kinda of messed up cause of the electrical short. im not sure till i can borrow an ecu to test it out.