Simple Alternator Replacement Turned Bad

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 9, 2010

#1

• Jun 9, 2010

• #1

Need some help. I replaced the alternator today and when I went to reconnect the negative battery terminal, the two wires that connect to the fuse box under the hood started smoking. Trying to find the problem, the only thing I noticed is that one of the wires is exposed just a little bit, but it's not touching anything else in order to ground or short out. So I disconnected both wires from the fuse block and reconnected the big red wire alone. Everything seemed fine. I had power and no smoke. Then I connected the small white wire alone and still no smoke. For some reason, when I connect the two of them together, I get a smoke show and no power to the car.

Anyone have any idea what's going on here? All wires to the alternator are connected properly.

 

wmburns

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

Jun 9, 2010

#2

• Jun 9, 2010

• #2

Post does not say the Model Year.

Pictures may help communicate exactly which wire is smoking.

I am not positive which white wires you are talking about. But it is likely to be the "fusible links" installed within the main alternator cable.

Start by measuring the resistance between the alternator B+ and a good chassis ground.

Did anything else happen during the alternator replacement?

If you disconnect the alternator B+ cable at the alternator and re-connect everything else, does it smoke? Possible the new alternator is bad?

 

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 9, 2010

#3

• Jun 9, 2010

• #3

It's a 97 GT 4.6L. I think it is the fusible link that I'm talking about. Everything was fine with the old alternator. Would a new alternator cause the fusible links to burn up?

What is the B+ cable?

 

wmburns

SN Certified Technician

Aug 14, 2009

5,892

514

204

Houston Texas

Jun 10, 2010

#4

• Jun 10, 2010

• #4

The alternator B+ cable is the main power cable to the alternator itself.

If the alternator is bad (internal short) it surely could cause an issue.

Consider taking the alternator to an autoparts store and have it bench tested.

 

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 10, 2010

#5

• Jun 10, 2010

• #5

Thanks!! I'll check the alternator when I get home from work.

 

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 11, 2010

#6

• Jun 11, 2010

• #6

About to take the alternator to get it checked now.

It is the fusible link that was smoking. Well it's the wires connected to the fusible link. Does this mean the link is blown? Here's a picture of the wire. It's burnt but not broken.

 

Attachments

• DSC03030.webp

  69.4 KB · Views: 221
• DSC03036.webp

  37.1 KB · Views: 207

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 11, 2010

#7

• Jun 11, 2010

• #7

Ok so I took the new alternator back to Auto Zone. It tested good so no internal short. When I took it off, I noticed there were a few wires that were exposed just a little bit. So I taped those wires up to include the wires on the fusible link and tightened up the connector for the alternator's ground. Put the belt back on and connected the battery and everything was fine! Started the stang and no problems!

I'm thinking the main problem was the ground on the alternator. The connection was not as tight as it could have been. Now I have the battery on the charger so it can fully charge so that I don't burn up the alternator!

Thanks to those who tried to help! Guess I shoulda double checked that ground before I posted huh!

 

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 12, 2010

#8

• Jun 12, 2010

• #8

DAMN! Just when I thought everything was good, I have another problem! So after charging the battery all night and realising it wasnt charging, I took it to autozone and it tested bad. Bought a new battery and hooked it up, car fired up but the damn battery light was still on. I checked the voltage and it was at 12.66 with the car off. Started the car up and it dropped to 12.36. I just had the alternator checked yesterday so I know it's good. I wiggled the wiring harness that plugs into the alternator and the voltage jumped op to 14 where it should be! So I guess I gotta splice in a new connector for the alternator! DAMN!!!

 

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 13, 2010

#9

• Jun 13, 2010

• #9

Well, I have a temp fix on it now. I realized that one of the wires that is in the harness was coming out so I tried to push it in as far as it would go. Hooked everything back up and everything is good for now. I'm still going to try to find another connector so I can get it right instead of hoping the wire doesn't come loose again.

 

hotdog71

Member

Dec 8, 2004

427

0

16

Seattle, Eastside

Jun 15, 2010

#10

• Jun 15, 2010

• #10

Hi,

It should be around 14V when car is running and charging and of course is around 12.5v give or take a couple hundred mV when car is not running. When starting it will drop to around 11.5V then jump up to 14V charging.

I had a bad bat a while back and it was dropping to 10.5V but charging at 14V so the bat was not holding it's charge.

Seems like your on the trail good luck!

 

M

Missinlinc

New Member

Mar 7, 2010

30

0

0

Georgia is home but the Army has me in San Antonio

Jun 15, 2010

#11

• Jun 15, 2010

• #11

Yeah man! Everything is good so far. Thanks!