short to ground blowing 350amp fuse

Are you sure you are getting the right part number? In your other thread you were dealing with a 400A fuse. Now a 350? I see some conflicting info online and need to check my own malibu to see. I will later today.

If you have replaced everything that you describe, there isn't much left other than the wiring itself unless there is something else on that circuit. As Campb said make sure you have the right amp fuse in that circuit. I don't have a wiring diagram of the circuit, but i am a master electrician and can help walk you through troubleshooting the problem. My first question is what all is on the circuit, if you know, and has it been modified in any way? Second have you run your hand down the wire for the circuit to everything it feeds and checked for cuts or places worn into the insulation etc? Also do you have any experience with a volt meter or amp meter or have access to one? Also does the fuse blow at random while driving or only when the starter is being used? Cheers

My 2017 1.5 also has a 400Amp fuse on the positive fuse block.

I have replaced the main positive wire to alternator and starter and just blew the 350 amp fuse again. Chevy has given me mtiple 350 amp fuse boxes and I never got a 400 amp fusebox and have gone thru 10 boxes. Starter alternator have been replaced

I can't even find the 400amp option online

Same... I searched all over and I can't even find the part with the original 400amp. That is my main concern. The original part has the 400 amp. Either 1) there is an error in the part catalog 2) at some point GM decided one block was fine for all trims and it isn't or 3) GM decided one block was fine for all trims and it is fine (meaning you have another problem). If 2, did it get fully tested? Was it even tested? All I know is the original part has the 400 in our model year. In the beginning the engineers decided the 2.0 and 1.8 were fine with the 350 but the 1.5 needed a 400. The 1.5 also has a different starter than the 2.0 and 1.8 which makes sense.

At this point you might consider taking it to GM and see if they can fix it. Maybe there is a calibration update that is needed to use the alternate part.

Is that fuse protecting the starter? If so what brand of starter was installed? Reman or new? I could see a reman. starter being defective as most reman parts are very questionable.

repairman54 said:

Is that fuse protecting the starter? If so what brand of starter was installed? Reman or new? I could see a reman. starter being defective as most reman parts are very questionable.

Click to expand...

The starter is the only thing it links to. The way I read the first post it blew then the OP changed the alternator, battery, fuse block a bunch of times then the starter. I totally agree on using a new OE starter though. I searched this forum and found lots of posts in gen8 but not much in gen9 - only one other post and it was a guy helping someone else.

Digging some more into schematics I see a diagram with KL9 and without KL9. With KL9 is 400A. Without KL9 is 350A. RPO KL9 is stop/start. I am curious if there are any mods in play we aren't aware of that complicate things. Perhaps GM did revise that block down to 350 and it is really borderline and something unexpected drawing pushes it over. I have particular interest in this because next week my battery fuse block could blow. I'd like to know what to do.

Perhaps you can find a 400 amp fuse box or just the fuse itself at a scrap yard/auto recycler.
Might want to check the ground path as well. Ground straps and all ground connections must be clean and tight. Electricity can do some funny things.

Dealer parts dept. will have a more precise part lookup possibly listing with or without KL9 option.
I'm thinking starter is pulling darn near the 350A so 400A is needed or starter is exceeding amp draw. Just because starter works doesn't mean it's not pulling too many amps.

Ambient temps of above 30F the normal current draw is usually not over 150 amps. Huge current draws only occur at extreme low temps.

A weak battery could cause high amp draw. Remove ignition fuse, have someone crank engine while holding a volt meter on the battery. Should easily stay over 10 volts. Try jumping from another battery, does it crank faster?

If ground is suspect. Connect one jumper cable to the case of the starter and touch the other end of the jumper cable to the negative of the battery. This is done with someone cranking the engine and the ignition fuse pulled. Does the cranking speed noticeably increase? This would indicate a bad ground.

Replaced the starter with a new one, hopeful this solved the issue. Should know within a week or 2 if it does not short the fuse by then it must have been a bad starter?
If anyone can find a400 amp fuse please post it for me to buy it 😆
FYI not sure if my original was 350 or 400
Had mechanics start this job and when I deemed them incompetent and just jacking up my bill with stuff I can do myself, I decided to finish it. Day 2 with new starter.