Keeps blowing Ignition fuse

Tiny
DADSBUICK
  • MEMBER
  • 2000 BUICK CENTURY
  • 88,000 MILES
I have a 2000 Buick Century that I am borrowing and it’s been nothing but a huge headache. The latest is the number 5 IGN-1 30A fuses keeps blowing. It has yet to happen to me but since having the car for 5 months it all of a sudden will blow this fuse when my wife uses the car. Mind you this car is completely stock meaning no aftermarket anything. It has happened three times so far. She will run to a store and when she returns to start it there will be nothing. No dash lights nothing. I’m perplexed. The only recent maintenance that has been performed is the rear brakes and a right front wheel bearing. I can’t seem to find an online wire diagram to trace out the paths to this fuse. The Buick has gotten worse and now has broken down on me. The 30A fuse will blow each time in the crank position. In order for me to get the car started I have to have a good fuse installed, turn the ignition key to the position right before crank and use a single wire touching the remote battery stud to the starter solenoid in order to bypass the ignition crank circuit. I appreciate the schematic diagram provided from above but the block diagram doesn't show the entire circuit I need. The other manuals Ive seen are the same way.

Any help is appreciated.
Sunday, October 16th, 2011 AT 5:27 PM

19 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 42,861 POSTS
Hello,

That fuse powers the ignition switch and everything associated with that system. But to me it seems like the ignitions witch itself is the problem if you look at the wiring diagrams (below).

I would do the ignition switch first (here are more diagrams (below)

Let us know what happens and please upload pictures or videos of the problem.

Cheers, Ken
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Tuesday, November 28th, 2017 AT 5:32 PM
Tiny
KWATHEY
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  • 8 POSTS
  • 1998 BUICK CENTURY
  • 86,000 MILES
I have a 98 Buick Century and have replaced the starter. The 40amp ignition fuse keeps blowing. All wires to starter are fine. Could the battery be bad? Any help would be great.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
SATURNTECH9
  • MECHANIC
  • 30,870 POSTS
Which fuse is it exactly?Its in the under hood fuse box?Its just labeled ignition or something else?Also does it blow as soon as you try to start it or does it blow over time.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KWATHEY
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  • 8 POSTS
It's under the hood and it's intermittently blowing. Just had battery checke and it's fine.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
SATURNTECH9
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Alright which fuse is it exactly what is it labeled as in the fuse box?Iam not there to see for my self so I need as many details as posible.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KWATHEY
  • MEMBER
  • 8 POSTS
40 amp ignition fuse under the hood near the battery
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KWATHEY
  • MEMBER
  • 8 POSTS
It's number 2 or 3, sorry don't know for sure at auto store
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
SATURNTECH9
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So the fuse will blow while driving down the road intermintly?Is it the number 8 fuse labeled ign 2 I just want to get all the facts straight so we dont go chasing the wrong wires.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KWATHEY
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  • 8 POSTS
It's number 2 and it blows while starting the car. I've replaced the starter and tested the battery and it's fine.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
SATURNTECH9
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I need to know for sure which fuse and if it just blows while driving down the road or some other time. Because the ignition 2 fuse doesnt feed the starter circuit and you said you tried replacing the starter the ignition 1 fuse feeds the starter.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KWATHEY
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  • 8 POSTS
It's number 2 and it's labeled crank. Sorry for missing that. Could the wire to the starter be the problem?
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
SATURNTECH9
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As you can see from the wire diagram I posted that fuse feeds power thru the crank relay out the yellow wire to the transaxle range swith then out the purple wire of that switch to the starter solenoid. So there could be a issue with that crank relay the fuse box the transaxle range switch the wire that go into the transaxle range switch or the wire that comes out of it.I would start by making sure the yellow wire and the purple wire aren't shorted to ground somewhere. Do this with the negative battrery cable discounted for saftey reasons. If I don't answer back for a while iam going to church soon and will get back to you as soon as I can but check that stuff out in the mean time and let me know what you find.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KHLOW2008
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Not likely to be a faulty battery.

The fuse supplies power to many components and one of it could be bad causing the problem.

You need to isolate the components to trace the cause of the problem.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KWATHEY
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  • 8 POSTS
How would I go about isolating. Can I get code from autozone and figure it out from that? Could ignition switch be the problem?
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KHLOW2008
  • MECHANIC
  • 41,815 POSTS
Such problems are due to a shorting somewhere and the ignition switch or power source is not likely to be the cause.

When does the fuse blow? Is it during cranking, while engine is running or when certain components are used?

There would not be any trouble codes shown for such problems, unless certain component is bad and triggers the MIL.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KWATHEY
  • MEMBER
  • 8 POSTS
I have problems with my windows not always working. I'm checking wiring between door jams now. Could I be on the right track?
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KHLOW2008
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It is possible the circuit is at fault but the power relay that the ignition turns on to activate the power windows has a 30 A fuse after it and the fuse should be blowing instead of the 40 A fuse.

Recheck the power window circuit breaker and ensure it is of the correct designation first.

Diagram shows the power distribution for the fuse and ignition switch. Any shorting along the lines would cause the fuse to break.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
SATURNTECH9
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Alright iam back if the ignition switch was bad the ignition 1 fuse would blow like khlow2008 said. You said this fuse only blows while cranking the engine sometimes so your best bet is to visually trace the yellow wire to the transmission range switch then from that to the purple wire to the starter looked for a chaffed/shorted wire to ground. That is where I would start I thinking looking in the jambs right now is barking up the wrong tree. Unless you were rolling down a window and fuse blew etc then I would look there. Because that fuse powers the crank relay that sends power thru the transmission range switch that sends power to the starter. So if that fuse blows while cranking only then it makes sense the problem would be where I said to look. Let me know what you find.
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)
Tiny
KHLOW2008
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Welcome back, lol.

Sorry I missed that part out. Yes, since the problem occurs only while starting, the starting circuit should be the first suspect. I agree fully with what Saturntech9 suggest with his latest reply. I
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Wednesday, November 29th, 2017 AT 10:56 AM (Merged)

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