How to replace 120A ALT fuse?
Thread Starter
Pit Crew
Joined: Dec 2003
Posts: 135
Likes: 11
From: Massachusetts
How to replace 120A ALT fuse?
Seems like a stupid question, but I have a blown 120A ALT fuse in my 93 SC300, it wouldn't pull out by hand, I can't see any clips on it, and it shattered easily when I used a pair of pliers. How does a person remove it?
FYI, I do have the battery disconnected, and I own the manuals but can't find them after our move from VA to MA.
My issues were similar to another thread, car not started for three months, seemingly dead battery, after/while charging the door open chime and door open dashboard symbol come on, the dome light and the lights at the bottom of the doors come on, and the horn blows. No other dashboard lights or electrical things work.
I cleaned the battery terminals, and the battery appears at full charge according to the rudimentary gauge on the charger. I noticed the blown fuse as soon as I opened the fusebox.
Previous to it sitting idle (shoulder surgery - it's a stick) it ran fine, but the AC had recently stopped blowing cold, although the fan and controls worked. I don't expect that's related, but I can always hope.
I have to go buy a new fuse anyway, so that will give me a clue about how it installs/removes before I go breaking other things.
Jonas
FYI, I do have the battery disconnected, and I own the manuals but can't find them after our move from VA to MA.
My issues were similar to another thread, car not started for three months, seemingly dead battery, after/while charging the door open chime and door open dashboard symbol come on, the dome light and the lights at the bottom of the doors come on, and the horn blows. No other dashboard lights or electrical things work.
I cleaned the battery terminals, and the battery appears at full charge according to the rudimentary gauge on the charger. I noticed the blown fuse as soon as I opened the fusebox.
Previous to it sitting idle (shoulder surgery - it's a stick) it ran fine, but the AC had recently stopped blowing cold, although the fan and controls worked. I don't expect that's related, but I can always hope.
I have to go buy a new fuse anyway, so that will give me a clue about how it installs/removes before I go breaking other things.
Jonas
Thread Starter
Pit Crew
Joined: Dec 2003
Posts: 135
Likes: 11
From: Massachusetts
Progress?
Okay, so I have the fuse block up from its box, the front separated from the back, and the screws/machine bolts removed from front and back under the fuse, as well as loosening the adjacent screws in case they were clamping the 120A fuse. Still no luck.
The local Toyota dealer (no Lexus dealers on Cape Cod) says they might have one, bring in the old one. The local parts store says they have no 120A fuses.
Thoughts?
Jonas
The local Toyota dealer (no Lexus dealers on Cape Cod) says they might have one, bring in the old one. The local parts store says they have no 120A fuses.
Thoughts?
Jonas
A couple of those are real head scratchers at first. You should be just about there... Once all the fuse housing is unclipped and pulled apart, you'll see two screws per holding a few of the fuses in, one on each side.
Thread Starter
Pit Crew
Joined: Dec 2003
Posts: 135
Likes: 11
From: Massachusetts
Thanks, I have those two screws out, but the fuse won't budge. If that's all that's holding it, I'll get more aggressive. All the plastic of the fuse seems very brittle, every time I try to use needle nose on anything it just comes apart.
Do you suggest I dig down to the metal pieces and get it out of there?
Thanks again,
Jonas
Do you suggest I dig down to the metal pieces and get it out of there?
Thanks again,
Jonas
Trending Topics
ClubLexus Stories
Celebrating Lexus & Toyota from Around the Globe
8 Tips for Improving Your Hybrid or Plug-in Hybrid's Efficiency!
Michael S. Palmer
10 Best Lexus Models No One Remembers
Joe Kucinski
TRD Off-Road Premium: Best 2026 4Runner, Except This One Thing
Michael S. Palmer
Top 10 Lexus & Toyotas to Drive Before You Die!
Joe Kucinski
Top 10 Lexus/Toyotas With The LEAST 5-Year Depreciation
Joe Kucinski
Lexus LC500 Convertible Auction: A Preview of Rising Values?
Brett Foote
GX 550 vs TX 550: Best 3-Row Luxury Lexus Family Hauler
Michael S. Palmer
9 Best Lexus Models You Can Buy for Half Price (And 1 You Shouldn't!)
Joe Kucinski
2026 Lexus NX Buyer's Guide: Models, Features, Prices & More!
Brett Foote
Thread Starter
Pit Crew
Joined: Dec 2003
Posts: 135
Likes: 11
From: Massachusetts
Guess I'll take the whole front of the fuse block out and bring it inside where I can investigate better and flip it upside down. I found a thread from 2010 on the GS forum which shows the same thing I'm doing, but my fuse won't let go. then there's the question of why it blew in the first place ...
Kinda screwed up my healing shoulder just holding the block while using the socket wrench to get the bolts out. Surgery & getting old sucks.
Kinda screwed up my healing shoulder just holding the block while using the socket wrench to get the bolts out. Surgery & getting old sucks.
Thread Starter
Pit Crew
Joined: Dec 2003
Posts: 135
Likes: 11
From: Massachusetts
"They bolt in from the bottom. "
Could you clarify that? Are you saying that in addition to the front and back bolts there is another that comes up into the bottom of the fuse? After ordering new fuses and viewing them online it appears that just those front and back bolts/screws hold them in place.
Could you clarify that? Are you saying that in addition to the front and back bolts there is another that comes up into the bottom of the fuse? After ordering new fuses and viewing them online it appears that just those front and back bolts/screws hold them in place.
As I figured. 
That whole piece in your hand comes apart, exposing screws underneath that hold the fuses in. I forget exactly how it releases, but there are a few tabs on it that should be self-evident.
That whole piece in your hand comes apart, exposing screws underneath that hold the fuses in. I forget exactly how it releases, but there are a few tabs on it that should be self-evident.
Thread Starter
Pit Crew
Joined: Dec 2003
Posts: 135
Likes: 11
From: Massachusetts
So, no, they don't "bolt in from the bottom" other than the two screws we've been discussing, and the pictures show I've already removed those two screws. At this point it should come right out, there are no tabs.
But, there's a small ridge on one of the copper legs caused by one of the screws which prevented it from coming out. I pushed it up from underneath with a small screwdriver.
Here's what it looks like, or what's left of it. RockAuto sells them for $1.87.
But, there's a small ridge on one of the copper legs caused by one of the screws which prevented it from coming out. I pushed it up from underneath with a small screwdriver.
Here's what it looks like, or what's left of it. RockAuto sells them for $1.87.
6th Gear
Joined: May 2025
Posts: 6
Likes: 0
From: Arizona
Very late to this thread, lol. If you use dielectric grease inside of the fuse port, and carefully wiggle the fuse prongs around, (assuming your fuse shattered like his and mine) it should come out after: removing the fuse block>removing the two 12mm on each side of the fuse. Use needlenose pliers to get a firm grasp, and remove in an upwards pull.
You can use an air compressor or vacuum to remove the little pieces that may have fallen into the port.
Hope this helps!🙏
You can use an air compressor or vacuum to remove the little pieces that may have fallen into the port.
Hope this helps!🙏
2nd gear
Joined: Apr 2026
Posts: 2
Likes: 0
120amp fuse
I have the same problem, stored car 4 months on trickle charger then discovered 120 amp fuse blown. Thanks for the info on removing the fuse. Followup, why did the fuse blow and did your car start fine after fuse replacement?