# AC Fuse blowing



## thomastricquet (Apr 20, 2019)

My wife's Cruze just started blowing warm air at its cold setting. The 10 amp fuse was replaced. AC was blowing cold for a week. This morning it stopped blowing cold air and the compressor doesn't activate. I replaced the fuse (this one glows when blown) and less than one minute it was blown. I am going to assume that there is a short somewhere. Any info on where to check before replacing the whole compressor?


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## plano-doug (Jul 1, 2015)

thomastricquet said:


> My wife's Cruze just started blowing warm air at its cold setting. The 10 amp fuse was replaced. AC was blowing cold for a week. This morning it stopped blowing cold air and the compressor doesn't activate. I replaced the fuse (this one glows when blown) and less than one minute it was blown. I am going to assume that there is a short somewhere. Any info on where to check before replacing the whole compressor?


I would look for a damaged wire going to the compressor. If it has been rubbing something, perhaps it's shorting to ground and causing the fuse to blow. Start at the compressor and trace the wire backwards looking for a bad spot.

I believe the only thing in the compressor using electricity is the clutch. I doubt it's drawing over-current, but if it is the culprit, you should be able to replace it without replacing the entire compressor (and having to vacuum and re-charge the system).

In normal operation, the engine moves around just enough that, if you have a damaged wire, it can cause the short to come and go and hence let the compressor work for a week, then move slightly to re-establish the short that's blowing the fuse.

If the harness to the compressor is damaged, it may need to be relocated - maybe it's missing a cable clamp somewhere that has resulted in it being exposed to a sharp corner somewhere.

It may be that the fix is a couple wraps of electrical tape and a couple zip ties to secure the harness.

HTH.

Doug

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## thomastricquet (Apr 20, 2019)

plano-doug said:


> I would look for a damaged wire going to the compressor. If it has been rubbing something, perhaps it's shorting to ground and causing the fuse to blow. Start at the compressor and trace the wire backwards looking for a bad spot.
> 
> I believe the only thing in the compressor using electricity is the clutch. I doubt it's drawing over-current, but if it is the culprit, you should be able to replace it without replacing the entire compressor (and having to vacuum and re-charge the system).
> 
> ...


Should I start the wire examination from the fuse box? I checked all fuses associated with the AC, both in the engine bay and in the dash.


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## plano-doug (Jul 1, 2015)

thomastricquet said:


> Should I start the wire examination from the fuse box? I checked all fuses associated with the AC, both in the engine bay and in the dash.


Start at the compressor and work backwards. Generally, the far end of the wire is where it's most exposed and hence most likely to get damaged.

HTH.

Doug

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## thomastricquet (Apr 20, 2019)

plano-doug said:


> Start at the compressor and work backwards. Generally, the far end of the wire is where it's most exposed and hence most likely to get damaged.
> 
> HTH.
> 
> Doug


This is what I saw When I started checking things out. Can I assume that the wire is not supposed to look like that? Is this strictly a electrical tape fix or more of a wire harness replacement? The wire in question is the wire in the lower slot with the brown colored bend,


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## plano-doug (Jul 1, 2015)

thomastricquet said:


> This is what I saw When I started checking things out. Can I assume that the wire is not supposed to look like that? Is this strictly a electrical tape fix or more of a wire harness replacement? The wire in question is the wire in the lower slot with the brown colored bend,<snip pic>


Let's back up a bit. When you replaced the fuse earlier, did you verify it was blown?

Looking at this, I see two possibilities. One is that the exposed wire is broken and making intermittent contact such that the compressor sometimes does not work. The other is that something not in the pic is touching the exposed wire at times and shorting the wire to ground thus blowing the fuse(s). But the latter is a stretch.

Could it be that it was just a coincidence that the compressor began working again when you put in the new fuse? When it later stopped working with the new fuse, did you verify it was indeed blown?

Looking at the pic, it's hard to be certain if the wire is broken, or just exposed. Also, I cannot see for sure, but it appears there is some sort of strain relief holding the wire in place. Is it metal? It's the grayish looking thing just to the right of the connector. It could just be a piece of wrapping coming undone off the cable.

Could there be another exposed section of wire on the backside out of view that's somehow shorting to ground?

Anyway, seeing the exposed wire makes me thing you are zeroing in on the source of the problem. Can you unplug it and inspect it more closely?

Doug

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## thomastricquet (Apr 20, 2019)

I'll check on it tomorrow when I'm done with work. To answer some questions..... I took it to a shop last week. They topped off the refrigerant, and changed the fuse. Said if it happens again it is probably a short or worse a bad compressor. It was blowing cold air immediately and you could hear the fluctuation of the compressor as it was turning on and off. When it started blowing warm air this morning, I checked the fuse and it was definitely blown. I replaced it with one that glows when it blows. when I turned on the AC, it still blew warm air. I looked at the fuse and it was lit. Literally 15 seconds passed by from inserting it in the block and turning on the AC. If it is not a broken wire, but merely exposed, would wrapping said wire with electric tape and replacing the fuse most likely solve, or am i looking at replacing the harness?


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## thomastricquet (Apr 20, 2019)

Also, the thing around the two cables I believe is a protective wrap, much like the ribbed hoses around other lines.


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## plano-doug (Jul 1, 2015)

thomastricquet said:


> I'll check on it tomorrow when I'm done with work. To answer some questions..... I took it to a shop last week. They topped off the refrigerant, and changed the fuse. Said if it happens again it is probably a short or worse a bad compressor. It was blowing cold air immediately and you could hear the fluctuation of the compressor as it was turning on and off. When it started blowing warm air this morning, I checked the fuse and it was definitely blown. I replaced it with one that glows when it blows. when I turned on the AC, it still blew warm air. I looked at the fuse and it was lit. Literally 15 seconds passed by from inserting it in the block and turning on the AC. If it is not a broken wire, but merely exposed, would wrapping said wire with electric tape and replacing the fuse most likely solve, or am i looking at replacing the harness?


If the fuse is blowing, there is likely a short to ground somewhere. The exposed wire in the pic may be a bum steer - it may not be the source of the short. I would disconnect the wire from the compressor and trace it back. If there's a short in it, there should be a spot on the sheath where the wire inside has been damaged. 

Wrapping the exposed section with tape is advised, but I doubt that fixes the problem. FWIW, I usually use Scotch 33+ . It conforms very nicely. There are automotive temperature tapes, too, but they're hard to find. I've had good results with the 33+ under hood. 

Rather than replacing the harness, I'm thinking it should be repairable.

HTH.

Doug

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## Slowbaru14 (May 14, 2020)

thomastricquet said:


> My wife's Cruze just started blowing warm air at its cold setting. The 10 amp fuse was replaced. AC was blowing cold for a week. This morning it stopped blowing cold air and the compressor doesn't activate. I replaced the fuse (this one glows when blown) and less than one minute it was blown. I am going to assume that there is a short somewhere. Any info on where to check before replacing the whole compressor?


Any resolution on this? Im working on this issue right now with my own


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