Hi all,
I have a fuse question:

I have an air compressor that connects to my car battery so I can air up my tires (Jeep).

It takes a 35 ATC fuse which I can't seem to find in any stores. All they have is 30 or 40, no 35. I ordered some online, but am going wheeling this weekend and looks like they won't get here in time.

When I was at Radio Shack, the guy there said just use a 30. Sure enough, the 30 worked briefly, but they seem to pop really easy and I went through 5 or 6 of them to air up 3 wheels.

So would a 40 work better until I get the 35's in the mail? Or is there a reason the Radio Shack guy said to get a 30 and not a 40?

Or if anyone has a store I can get a 35 in? I've tried Home Depot, Lowe's, Pep Boys, Auto Zone, and Radio Shack.

 

Welcome to the forums! The reason the RS guy steered you to the 30 amp fuse was for safety purposes. If the unit calls for a 35 amp, it is better to under fuse it than to cause wiring to melt by using too large a fuse. I believe, however, if it is blowing 30 amp fuses, 35 amp fuses won't make much difference. You really have a load on there. Is it a factory unit, or has it been modified? If you choose to use a 40, keep an eye on the wiring to make sure the pump is not pulling too much amperage. If so, it will cause a problem with the wiring from and to the pump. The smaller wire becomes your fuse at that point.

 

It hasn't been modified.

Part of the reason it's probably blowing fuses is because the power switch is broken, it is always in the 'on' position. So the way I turn it on and off is by connecting the positive clip to the car battery. When I want it off, I un-clip. If a fuse is going to blow, it will do it when I reconnect it.

Two 35 amp fuses lasted me around 4 months, whereas the 30 amp lasts pretty much through one disconnect and reconnect. So that's why I figured maybe the 40 would be better than the 30.

Yeah, I know I should either fix the switch or buy a new compressor. I'm trying to avoid buying a new one right now. I have two weekends in a row that I will need the compressor. After that, I will probably try to replace the power switch (assuming radio shack carries something similar).

 

Safety purposes? Maybe, but I think he recommended the 30 amp fuse because he had them in stock and made a sale. I am no fan of Radio Shack, too many bad experiences with the dumb*** cheap ***tards.

 

So will I be ok with a 40 fuse for one trip? If I have to get the 30, I'm probably going to need a dozen of them for 4 tires.

 

I would buy a couple of dozen 30A fuses, just to be sure. I would not install a 40A fuse if it was handed to me for free. Burning up the wiring harness in my Jeep is not my idea of a fun wheeling weekend.

I think the RS clerk did his job just the way he should have. I'm wondering what your reaction - and your attorney's reaction - would be if he had sold you a 40A fuse, told you there was no danger in using that in an app that specified 35A protection, and then your Jeep's wiring had caught fire before the fuse blew.

I think that clerk protected himself and his company by protecting you.

 

Ok, that makes sense. Glad I asked and didn't just try it and cross my fingers (and wires lol).

I ordered a 2nd pack of 35A fuses from a closer place, hopefully they will make it in time. If not, I'll wait until Friday afternoon to hit Radio Shack and pick up a bunch of the 30's.

Thanks all for the help! This forum is proof that I shouldn't be messing with loose wires.

I still want to try to repair the power switch though. I work with computers, but yeah, electricity is a whole different ball game.

 

A lot of people don't get that. I'm glad you do.

 

That might be why it is blowing the fuse. It might have too much head pressure and is locked up when you reconnect. Wait a few mins. before reconnecting.

 

I used to work for RS.. Trust me, 99% of the associates would've sent him somewhere else for the proper fuse. We always hated people who came in for a battery or fuse because one of the metrics they track is "Dollars per ticket" - and a $2 pack of fuses with no add-ons kills your average - especially if you get a string of them in a row. It's not worth the 5¢ in commission for the hell we'd get at the monthly meeting for having a low $PT. He was being helpful, he didn't do it for the sale.

Rick, I would try an actual car audio shop. Not bestbuy, one of the hole-in-the-wall places that does installs. 35A is a common size for amplifiers.

 

If you're turning it on and off by connecting directly to the car battery with clamps, the only possible damage that will be done with a 40-amp fuse is to the compressor wiring. It won't hurt the Jeep's wiring at all.

However, connecting to a car battery has its own potential dangers. Believe me -- I've been on the receiving end of a car battery explosion. Wear safety glasses. Seriously. You can wash battery acid off your skin, and you can shed your clothes in a hurry. But you can't get it out of your eyes fast enough to prevent permanent damage. Thank God I was wearing sunglasses!