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Blow my fuse..

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Just 1 More

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Discussion starter · #1 ·
So I take the Camaro to a cruis-in tonight, everything was just fine, left there and stopped at the grocery store, came out and tried to start it and it was dead. Blew the main fuse at the battery. Replaced the fuse and started right up. Drove home, parked in the garage, shut it off, tried to crank it back up, blew the fuse again.
The fuse blows immediately as the starter engages as if the starter is suddenly drawing too much amps. It's a 200amp glass block style. It's been just fine the past 2 years that it's been set up this way so i'm at a loss as to why all of a sudden there's an issue. looks like i'm trouble shooting this weekend
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#2 ·
It’s a female fuse holder.
Just because you didn’t do anything different doesn’t mean it’s going to respond in a logical rational manner!
Damn Frank, that’s some crazy luck.
My worn out shot in the dark….check connections for tightness and carbon arcing. Resistance is relative to an increase in amperage required.
I like no-ox on electrical connections.
im definitely interested in your findings 👍🏼
 
#3 ·
Do you have or have access to an Amprobe clamp on amp meter? I would connect the starter cable directly to the battery (while testing) and check your cranking amperage. My guess is the starter is pulling higher than 200 amps. Just wondering... is your starter a gear reduction type? I understand they draw less amps than the OEM type.
 
#5 · (Edited)
This is why you don’t see the OEMs fusing the starter motor imho. Fusing current of a fuse falls with temperature rise above ”room temperature”.

Some kind of slow blow fuse would be more appropriate but I’m not sure if they are available with that kind of current rating.

Use a 400 amp fuse… 🙂
 
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#6 · (Edited)
jimsl78 said:
Do you have or have access to an Amprobe clamp on amp meter? I would connect the starter cable directly to the battery (while testing) and check your cranking amperage. My guess is the starter is pulling higher than 200 amps. Just wondering... is your starter a gear reduction type? I understand they draw less amps than the OEM type.
Click to expand...
I’m not sure a current meter will catch what is going on here…

Don
 
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#8 ·
jimsl78 said:
With the fuse bypassed you can crank long enough to get a reading. I'm not sure, but I think most newer Amprobes have a feature that will record the highest reading.
Click to expand...
I think you will measure the rms or average current depending on the meter. That may or may not be exceeding the fuse rating.

Don
 
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#9 ·
This thread is “Patrick bait”… 😂
 
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#13 ·
Interesting reading….
www.chevelles.com

I am Suprized at the amount of Starter current

I have wondered for some time how much current the starters on our cars actually draw during the start up process. I went out today and measured the whole start up sequence of my 69. Here are the results: I have expanded the first 20 milliseconds so you can see better what happens. This...
www.chevelles.com www.chevelles.com
 
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#14 ·
Just 1 More said:
Based on what Don and John are saying, just remove the fuse and attach directly... ok, i'll try it.
Click to expand...
Well, I wouldn't go doing that necessarily. If it's blowing and it didn't before, something's wrong - I'd look for a short to ground first. 200 amp fuse should run a starter fine long enough to get the car running. I'm sure that fuse is going to blow as soon as it goes over 200 amps, its a thermal device and will take a while to trip, certainly not the few seconds it takes to get a warm engine started.
 
#15 ·
srode said:
Well, I wouldn't go doing that necessarily. If it's blowing and it didn't before, something's wrong - I'd look for a short to ground first. 200 amp fuse should run a starter fine long enough to get the car running.
Click to expand...
I respectfully disagree. The data in the Chevelle thread says otherwise.

Fuses should be derated by at least 50%, ideally 100% imho….
 
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Discussion starter · #16 ·
I removed the fuse block and went straight to terminal and now starts great. Reading the Chevelle post it seems a 250amp fuse would work so maybe my fuse was too small, and the starter getting older is creating more drag... idk
 
#17 ·
dhutton said:
I respectfully disagree. The data in the Chevelle thread says otherwise.

Fuses should be derated by at least 50%, ideally 100% imho….
Click to expand...
We will agree to disagree (respectfully of course) even though you know much more than I do about electronics. The car started fine for 2 years and then suddenly not - so something changed and bypassing a fuse could have some serious consequences, figure out what changed and address that first. It could be the starter is toast, or a short to ground or other things.

That chart from the Chevelle forum is looking at amperage spikes in milliseconds and sure there's an amp spike, there is for any electric motor. Not enough to melt a thermal fuse appropriately sized for the wire. If that were the case I'd blow fuses every time I turned on an aerator or started the trolling motor on my boat.
 
#18 · (Edited)
Just 1 More said:
I removed the fuse block and went straight to terminal and now starts great. Reading the Chevelle post it seems a 250amp fuse would work so maybe my fuse was too small, and the starter getting older is creating more drag... idk
Click to expand...
"This is Patrick bait". It is all Mr. Don Hutton's fault you have to read my stupid story.

I have a neighbor boy that loves to fish. When the neighbor boy was five or six years old, the father cut the barbs off his hooks. The dad did not want to touch a live fish. The boy would go to the pond and cast and cast and never pull in a fish. So, when the boy got older, he got his mother to buy him a seine net.

Putting a fuse between the battery and the starter is kind of like cutting the barbs off a hook. You think you are fishing; you get a bite, but you don't reel in a fish. You think you are going to start your car, it kind of turns over, but the motor does not start. Buying a seine net is like taking out the fuse. You are going to catch something, and your motor is going to start.

The only thing that really changed is the battery. It is a year older. The battery cannot maintain its voltage. It is not a big difference, but it is enough. The starter turns slower because of the weaker battery. This causes the amperage to stay at an elevated level for a longer period of time. The longer period of time gives the fuse time to heat up and melt.
 
#19 ·
just like us, car parts get older and don't work as they did when they were new.

My $.02 is that fuse between starter and battery is not needed and may now be "the problem" due to age, use factors of battery and starter and starter cables.

Regarding starters, a true gear reduction starter will crank faster than a standard one. I ordered mine from Rockauto for around $80

This is a cross reference chart for Remy starters for conventional and gear reduction.
 

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#20 ·
What size cable are you running to the starter ?.

You never want to put on a fuse that is larger than what the cable can handle but if it is large enough, then it might just be a simple upsize on the fuse.

GM, and others are slowly putting more and more starter cable fuses on their vehicle and while I have not come across what size and length cables are being run off of the fuses, the 2017 and 2019 Camaro's for example with the battery in the trunk have a 350A fuse.


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And also on some Chevrolet Cruze vehicles:

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Jim
 
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