Welcome to the North American Subaru Impreza Owners Club Thursday August 17, 2017
Home Forums WikiNASIOC Products Store Modifications Upgrade Garage
Go Back   NASIOC > NASIOC Technical > Electrical & Lighting

Welcome to NASIOC - The world's largest online community for Subaru enthusiasts!
Welcome to the NASIOC.com Subaru forum.

You are currently viewing our forum as a guest, which gives you limited access to view most discussions and access our other features. By joining our community, free of charge, you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is free, fast and simple, so please join our community today!

If you have any problems with the registration process or your account login, please contact us.
* Registered users of the site do not see these ads. 
Thread Tools Display Modes
Old 04-11-2004, 11:55 PM   #1
Scooby Specialist
Member#: 16980
Join Date: Mar 2002
Location: QC, Canada
Default Fuses ? how do they work ?

ok ... so i'm having this electrical problem where my HKS CAMP is not starting some times See this thread for more info so, since the CAMP system (a car computer) has a fuse of 1.5amps on its ACCESSORY and ALWAYS ON wires, i was wondering how it worked,

these two wires are plugged on my radio wiring harness wich is rated at 25amps (?) i beleive (the stock fuse is a 25) ... not sure,

how is the current distributed in these wires ? does that fuse actually restrict the curent to 1.5 amps ? or is the unit only taking 1.5 amps and thats the only thing thats being pumped in those wires ???

now if i plug something else behind that 1.5Amps fuse... will it be underpowered since that fuse was only ment to power the original component it came with ?

a bit confusing i admit, but its hard to put in words ... let me know,

thanks guys
* Registered users of the site do not see these ads.

Last edited by Extraze; 04-12-2004 at 12:00 AM.
Extraze is offline   Reply With Quote
Sponsored Links
* Registered users of the site do not see these ads.
Old 04-12-2004, 06:58 AM   #2
Trust no one
Member#: 11170
Join Date: Oct 2001
Chapter/Region: Tri-State
Location: NYC
02 WRX
15 WRX/05 GTO


The rating of a fuse means it will allow up to that amount of current to flow through it. If the current exceeds that amount the fuse will blow, or open up. As long as the current remains under the fuse's rating it is essentially like a wire in the circuit, it doesn't limit current otherwise.
Each device will draw a specific amount of current when connected to 12V, this is a function of the electronics of the device itself and does not change if it's on a different fused circuit.
When connecting devices to a fused circuit the total current demand of everything on the circuit must not exceed the rating of the main fuse on that circuit. Good practice dictates that a certain safety margin should be maintained between the expected current draw and the fuse rating, generally 50% headroom (the fuse value should exceed the current draw by 50%). A little more or less is ok but the idea is not to run the circuit anywhere near its maximum rating.
In addition to the main fuse in the circuit, each device may have its own lower-rated fuse to protect it.
Mulder is offline   Reply With Quote
Old 04-12-2004, 07:54 AM   #3
Scooby Specialist
Member#: 42569
Join Date: Aug 2003
Chapter/Region: TXIC
Location: M-Dub & L-Town
adds to the douchery
level round' here...


Here is a bit of the same, different, more info How wires, fuses, and connectors work.
collegedropout is offline   Reply With Quote
Old 04-12-2004, 12:50 PM   #4
Scooby Guru
Member#: 44168
Join Date: Sep 2003
Chapter/Region: SCIC
Location: In your pant[ie]s.
2017 Silver Forester
with not enough lights...


Yep, the fuse doesn't regulate flow, it prevent's overflow (by popping, blowing, burning out, opening up, etc...) so the overflow doesn't blowor damage the device. The device itself will determine how much electricty it will pull through the wires and fuse.

[then again if you have a device pulling through much current through an underrated fuse, you'll pop the fuse that way too...]
Psydotek is offline   Reply With Quote

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
TD05 18G 7cm2 turbo: who has one and how do they work out for you? GDAryder Factory 2.0L Turbo Powertrain (EJ Series Factory 2.0L Turbo) 29 09-22-2008 12:20 PM
Strut tower bars - How do they work? Alan l. Brakes, Steering & Suspension 18 11-02-2006 03:02 PM
Bellagio garden water acs - how do they work? Sausage Off-Topic 17 10-20-2006 01:53 PM
Koni Inserts...how do they work? HiVoltg12 Newbies & FAQs 3 02-11-2004 03:56 PM
Adjustable sway bars - how do they work? tomrichardson Brakes, Steering & Suspension 5 05-03-2001 12:56 AM

All times are GMT -4. The time now is 02:12 PM.

Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2017, Jelsoft Enterprises Ltd.
Powered by Searchlight © 2017 Axivo Inc.
Copyright ©1999 - 2017, North American Subaru Impreza Owners Club, Inc.