serious alternator problem

[rktmn]

After I did my ATX/MTX swap, the alternator light on the dash has always been on; however, the the alternator seemed to charge the battery fine. This alternator lasted for about two years until it finally gave up. Since I had a lifetime replacement at Pep Boys, I was able to get another one for free.

I replace it, and it worked fine for about 2 months, until this one talso died.
I made it home one night as the headlights dimmed and finally went out as I pulled into my driveway.

Back to Pep Boys for another one. This time I got a Bosch rebuilt. The quality on this one seemed better. Immediately on hooking it up, the charging light on the dash went out, which leads me to beleive that the other alternators were putting out enough amps to charge the battery enough to keep it going, but not enough to make the light went out.

I ran this Bosch alternator for about 2 weeks, and last night I opened the hood to check the water in my leaky radiator, when I noticed that the output connector on my amp was glowing bright RED. The nut that holds the charging cable was white hot! This was about 2 or 3 minutes after starting the car up.

I immediately turned the car off. The cable had begun to melt at the connection, but I turned it off before there was any serious damage.

This leads me to beleive that the problem is comming from the alternator itself. If the short had been with the wiring harness, the cable would have melted at the other end.

The charging light did not turn on. I had my lights, A/C and stereo on at the time, but like I said, the car could not have been running for more than a couple of minutes before I open the hood and noticed the glowing connector.

I am sure that if I had not opened the hood to fill the radiator, my SHO would have caught on fire.

I will check it again when I get back from work today, but it looks like this alternator is no good.

Any electrical help would be appreciated, since this is not my strong point. I had been considering running a 00 gauge cable directly from the alternator output to the possive post on my battery before this happened. I have done this on my other cars with no poblems.

Any ideas as to what could cause this dangerous situation? Is it the alternator that is bad, or is it my wiring harness that is damaging the alternator?

Help!

Jose

 

[SHOZ123]

The only reason that would be hot like that is from too much resistance. The point where it is hottest is the point of maximum resistance. Sounds like the nut was loose or the cable is about ready to break. At any point the cable end is probably ruined now.

 

[rktmn]

You're right Paul, the nut is loose. There is some damage to the wiring, but I think that I cans save it. The alternator seems to have the stud spinning loose.

I will check it this week end and see what I can do to save it. I may go ahead and run a 00 wire straight to the battery.

Jose

 

[rktmn]

Thanks.

 

[rktmn]

Just an update, with a solution, to my alternator problems:

I instaled a #1 gauge wire going from the alternator output to the + post on my Optima battery. What a difference!!!

The headlights are much brighter, my stereo has more oompf, and my SHO seems to have more horse power.

I had always felt that the charging system on my SHO was lacking. I have been complaining about dim headlight for months, and now the improvement is awesome. Am am definitely going to get some brighter bulbs and polish the headlight lenses.

Voltage output at the battery is the same as before the addition of the thicker gauge wire, but I am sure that the amperage going into the battery has to be much greater.

I first noticed it when the underhood light bulb was no longer dim yellow, instead it is now shinning white for the first time. It is noticeable even during the day.

I am sure that this increase in current has given a boost to my fuel pump and ignition. I would also guess that the spray pattern in my injectors may have also improved, if the fuel pressure is higher and more consitant.

As I turn on the accessories, A/C, headlights and stereo, voltage drops from 13.80 to 12.56 at idle, but as soon as I rev the engine past 2500 rmp, it scoots back up to 13.50 Volts. I have not seen it reach 14V even with everything off or while reving the engine.

I am very happy with this simple mod. I have done this on several of my other cars in the past, but this SHO has definitely shown the greatest improvement.

Perhaps my charging system is old and tired, and bypassing it with a direct, low resistance connection fixed it.

Next I will add a negative #1 wire and ground it right to the engine.

Jose

 

[ViPER1313]

You know you are bypassing inline fuse on the positive cable by doing this, right? Check the connections on your starter - I would bet that is where you are loosing voltage in the positive cable. If not, instead of running 1ga straight from the alt. to the battery, run new cable / inline fuses to the fuse box under the hood, to the starter and then back to the battery so that it is done correctly. Exploding battery = nones the cool .

For reference, stock positive wire path is:

Alternator->Fuse link->Engine Compartment Fuse Box Post->Starter->Battery
(--------------------- Cable 1 ------------------------) (Cable 2) (Cable 3)
(-------------------Black/Orange----------------------) (-Red-) - (-Red-)