12v fuse question

[Steve in VA]

I have a 12v air compressor designed to draw from an automotive outlet. The fuse recently failed. There was a replacement in the kit. My problem is that I find no marking on either fuse as to their size. Both are the older style glass fuse. The manual doesn't provide a size.

How can I gauge a spare fuse? Is there a standard?
TIA.

 

[guido]

Steve in VA,

I would think that a 10 amp slow blow fuse may work, just a guess,

Guido.

 

[Blue Jay]

Look for the size on the metal end, sometimes hard to read.

 

[rustred]

what does the fuse panel say for that fuse ? on them glass fuses the thicker or wider the element the high the amp fuse. is that like a cigarette outlet? i am thinking at least 20 amp fuse. them glass fuses are marked on the ends what amp they are.

 

[TimV]

What's the brand of the compressor--just wondering if there's any online info available that may not be in the manual. Failing that, see if you can find what your vehicle's power outlet circuit takes--they're typically fused also--and pick one slightly below that.

 

[Dingo3]

Should be something stamped on the comp. that says how many amps it draws.

 

[Steve in VA]

All good advice guys. Here's an update:

The brand is Victor Quik-Aire. Online everything is newer than mine.

No markings on either fuse end caps. I broke out the magnifying glass and there is nothing.

The car manual list fuses for 2 of the 3 outlets [ go figure]. 10 and 20 amp. Tomorrow I'll pull each I turn and see which one actually works the cargo outlet.

Thanks so much guys. I really appreciate the help.

 

[UncleTom]

Those style of fuses are junk. I have had many that the fuse holder doesnt make good connection and build up heat until it melts on one end and not really blowing.

 

[guido]

Steve in VA,

Why not use an available fuse style.
Cut the wire and install the wire ends that fit the fuse?

Guido.

 

[DoubleO7]

I read your quandry as looking for the size of fuse that the compressor came with and not the fuze to the power outlet??
Is there no tag or label on compressor with volts and watts listed? If not amps.

When you find the fuse for the outlet, put in a 5 amp or ten amp.
Then run the compressor. If it blows the 5 then try a 10. If you have spares for the outlet.

This post was edited by DoubleO7 on 11/16/2022 at 03:16 pm.

 

[Steve@Advance]

If it were mine, I would be tempted to just bypass the fuse.

The circuit in the vehicle is fuse protected, so if there is a serious problem in the compressor, that fuse will save the wiring.

If the compressor is failing there is probably no fixing it anyway.

 

[Janicholson]

As noted below, start with a 5 amp fuse (that fits the clean holder). If that blows use a 7.5 fuse. (voltage on a fuse does not matter). If the compressor is football sized, and has 16 gauge wires going to it, it should run with a less than 10 amp fuse. If the compressor can run, even for a short time, it might be worth putting a 10 amp fuse in it. Good luck. Jim

 

[Steve in VA]

You are correct that I am chasing the compressor fuse. I checked the vehicle fuses because, as suggested, the comp fuse shouldn't be so big that it relies iron the car fuse for protection.

 

[MarkB_MI]

The fuse blew for a reason. My guess is the compressor is toast. It probably has a five amp fuse, which would be about right for 18 gauge wire.

 

[John T]

Mornin Steve, I would start with the fuse was sized to protect the wiring to the compressor so it should be rated no more than the wires ampacity. If you know the wires ampacity try a fuse that size for starters. I have seen so many of those 12 VDC compressors fail so that may well be the problem. Another attempt would be to use a Slow Blo that will allow for a higher initial start up surge when the compressor starts. Not knowing the wire size or compressors requirements Id take a pure engineers guess start with maybe a 7.5 then a 10 amp probably no greater than 15 amps BASED ON WIRE SIZE !!! DONT EXCEEED ITS AMPACITY !!!

Best I have to offer absent any specs or data or wire size and again the compressor may be fried grrrrrrr

John T Live in the RV overnight in a church parking lot in Longview Texas

 

[Geo-TH,In]

The outlets on my GMC has a 10a fuse with 10 amps which isn't enough for most 12v compressors.

I added wire to my 12v compressor and added alligator clips so I can wire the compressor directly to the battery.

I carry the compressor in my truck and have only used it once in 15 years..

My cadillac xt5 doesn't have a spare, instead it has a 12v compressor. I put 2 cans of fix-a-flat next to the compressor.
It has 60k and so far no flats.

 

[guido]

Steve in VA,

I would use one of these, as I said, and wire it in,

Guido.