Electrical issues after connecting the alternator with the battery connected

Tiny
CORY WEBSTER
  • MEMBER
  • 2008 SCION XB
  • 2.4L
  • 4 CYL
  • 2WD
  • AUTOMATIC
  • 200,000 MILES
I recently replaced my tensioner and drove my car and it was running great, but the battery light came on and wouldn't go off. So, I replaced the serpentine belt and the alternator but as I was connecting the alternator, I heard a spark and noticed I forgot to disconnect the battery cables and now only the dash lights and dome light and headlights work but nothing else. When the switch is in the "on" position the battery indicator light is not on. Is this possibly an electrical issue that can be easily resolved? Please, I need my car to get around in.
Friday, March 25th, 2022 AT 6:44 PM

16 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Hi,

There are several fuses related to the alternator. I would suggest starting with them. However, one specifically stands out. There is a fusible link between the battery and the fuse box. I would think a smaller fuse before it failed, but anything is possible.

I attached the wiring schematic below for your reference. I highlighted the fuses to check and the fusible link.

Pic 3 shows the location of the link and fuse in the under-hood fuse box to check. Pic 4 shows the fuse panel in the vehicle.

When you check the fuses, it will be important that you also confirm there is power to and from it even if the fuse is good. If there is no power, I will have to work backward to determine the power came from and if there is a fuse before it that may have failed.

Here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know what you find or if you have other questions.

Take care,

Joe

See pics below.

Images (Click to make bigger)
Thumb
Thumb
Thumb
Thumb
Was this
answer
helpful?
Yes
No
Friday, March 25th, 2022 AT 8:25 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
Thanks. I will check it in the morning and reply again.
Was this
answer
helpful?
Yes
No
Friday, March 25th, 2022 AT 9:35 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Hi,

No problem whatsoever. Let me know what you find or if I can help.

Take care,

Joe
Was this
answer
helpful?
Yes
No
Saturday, March 26th, 2022 AT 5:13 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
Haven't been able to figure it out yet.
Was this
answer
helpful?
Yes
No
Tuesday, March 29th, 2022 AT 10:36 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Cory,

Have you been able to perform the tests I suggested above? If so, what were the results?

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Wednesday, March 30th, 2022 AT 7:22 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
I haven't been able to yet.
Was this
answer
helpful?
Yes
No
Wednesday, March 30th, 2022 AT 9:19 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Cory,

No problem. When you have a chance, let me know. Hopefully, we will be able to get things taken care of.

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Thursday, March 31st, 2022 AT 1:24 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
Hi Joe, I finally got it I took the plastic cap off the fusible link and checked the highlighted section and that was it so I just put a flathead screwdriver in between it, and it cranked right up. But how do I fix that section without replacing the whole link?
Was this
answer
helpful?
Yes
No
Saturday, April 9th, 2022 AT 12:54 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Hi Cory, the link should be replaced with the same exact size/amperage. There really isn't a way to fix them that one would consider safe simply because it is designed to fail before damage to the wiring or a fire can start.

If possible, take a pic of the failed part. Also, see if there is a part number on it and I'll do my best to get you fixed up.

Take care and I'm glad you found the cause.

Joe
Was this
answer
helpful?
Yes
No
Saturday, April 9th, 2022 AT 9:06 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
Joe, I hope nothing happens but I soldered it.
Was this
answer
helpful?
Yes
No
Tuesday, April 12th, 2022 AT 2:44 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Cory,

If you soldered it, there is no way of telling how much amperage is required for it to fail again. If something fails or shorts, it may not fail and cause other electrical damage or even a fire.

Do me a favor. Take a pic of it and upload it for me to see what was done. I'm concerned of a short that can't cause link failure.

Let me know.

Joe
Was this
answer
helpful?
Yes
No
Tuesday, April 12th, 2022 AT 8:05 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
Okay, I will do that because I'm concerned now too.
Was this
answer
helpful?
Yes
No
Friday, April 15th, 2022 AT 8:49 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Sounds good. I will watch for your reply.

Take care,

Joe
Was this
answer
helpful?
Yes
No
Saturday, April 16th, 2022 AT 4:38 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
Here it is.
Image (Click to make bigger)
Thumb
Was this
answer
helpful?
Yes
No
Saturday, April 16th, 2022 AT 5:07 PM
Tiny
CORY WEBSTER
  • MEMBER
  • 16 POSTS
Picture is not the best but I haven't had any problems yet and it looks better in person, but I am concerned now that you have told me that.
Was this
answer
helpful?
Yes
No
Saturday, April 16th, 2022 AT 5:10 PM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,119 POSTS
Hi Cory,

I don't mean to make you worry. I just don't want something to happen. Listen. I looked at the pic and see what you did. I also see a somewhat long portion of the original fusible link is still intact. In my mind, that undamaged section should fail as designed because it is still original.

However, if you were a family member, I would still want you to replace it. I hope that makes sense. I feel it's okay for a while, so don't worry, but I would like to see you replace it when you can.

I'm here if you have questions, concerns, or any issues, so don't be afraid to get in touch. You are always welcome.

Take care of yourself, and I wish you and your family a Happy Easter,

Joe
Was this
answer
helpful?
Yes
No
Saturday, April 16th, 2022 AT 6:40 PM

Please login or register to post a reply.

Related Alternator Replace/Remove Content

Alternator Replacement
VIDEO
Alternator Replacement
In­struc­tional re­pair video
Alternator Replacement
GUIDE
Alternator Replacement
Got a red bat­tery warn­ing light on? This most likely means the al­ter­na­tor has gone out and needs a re­place­ment. To con­firm the fail­ure use a volt­meter to test the al­ter­na­tor...