fuses lowering voltage?
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=94975
Printed Date: May 15, 2024 at 5:49 AM
Topic: fuses lowering voltage?
Posted By: jmelton86
Subject: fuses lowering voltage?
Date Posted: June 21, 2007 at 3:25 AM
Just a simple question. Upon adding 150a AMG fuses about 18" from front and rear batteries (yellowtops, no isolator/circuit breaker. dist block about 18" from rear fuse holder) I noticed a .3 voltage drop. Before fuses (straight wire between fr and rr batteries) the idle voltage stayed at 14.7, now it stays at 14.4v. During bass peaks it would drop to 14, now to 13.8. Details: I used standard Bussman AMG fuses (copper) and standard copper lugs that I sanded down for best connection. -Is the fact that I used copper lugs and fuses the reason? If I used gold plated ones would it help? Thanks, Javin ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Replies:
Posted By: DYohn
Date Posted: June 21, 2007 at 9:50 AM
No, there is no real difference in resistance between copper and gold-plated lugs. Gold just resists corrosion better. While any connection can cause a voltage drop, that does seem rather large for a fuse or fuse holder. Did you happen to use slo-blo fuses? They sometimes have a coil inside that might cause this. If so, change to standard or fast-blo and see if it helps. Did you change anything else in the system? ------------- Support the12volt.com
Posted By: jmelton86
Date Posted: June 21, 2007 at 6:54 PM
I used standard AMG(wafer type) 150a copper-colored fuses. I used RF 4g cable from batts to fuseholders, then MonsterStandard 4g in between. I used regular 4g copper lugs for all connections. During both low and heavy loads the difference stayed about .4v lower on average. I didn't change anything else. ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: sparkie
Date Posted: June 21, 2007 at 8:57 PM
A small voltage drop is normal across any connection, fuse, switch, etc. The acceptable limit is 0.5 volts maximum from one end of the circuit to the other.
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sparky
Posted By: jmelton86
Date Posted: June 21, 2007 at 9:18 PM
I forgot to mention in the first post. Before the fuses, I had all 17' of the power wire ran even though I only needed about 10'. Meaning, I had about 5-7' of wire just coiled under the rear seat. When I added fuses, I was able to remove about 5-7' of wire! I would think that in itsself would increase voltage! Also, when I added the fuses I added larger grounds for rear battery and amps. -Had Big3 done before adding fuses. Volt gauge is in rear, connected to distro-block. ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: aznboi3644
Date Posted: June 22, 2007 at 5:27 PM
when I use copper lugs I always sand down the conact areas so they are nice and clean and don't have that thin layer of whatever it is
Posted By: jmelton86
Date Posted: June 23, 2007 at 2:47 PM
aznboi3644 wrote:
when I use copper lugs I always sand down the conact areas so they are nice and clean and don't have that thin layer of whatever it is
I did do that. Thanks. though. ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: mike swanson
Date Posted: June 24, 2007 at 1:30 PM
Did you upgrade the power wirer and ground from the +batt to the alt/from the -batt to the frame ?
This works very well
Part of the big3
Posted By: hustlin247
Date Posted: June 25, 2007 at 4:25 PM
You probably have this covered but i replaced the rusty corroded blocks of lead that were my battery terminal connectors with tsunami gold clamps and I gained a half a volt. ------------- '94 Ford Explorer / Kenwood KVT-815DVD / RF Power T1682C 6x8 (all doors) / RF Power T10001 / 12" Kicker L5 (x4) / Optima Yellow Top Battery
Posted By: jmelton86
Date Posted: June 25, 2007 at 6:31 PM
mike swanson wrote:
Did you upgrade the power wirer and ground from the +batt to the alt/from the -batt to the frame ?
This works very well
Part of the big3
Yes, I did. I used 4g (only 105a factory alt.) and copper lugs (sanded down for connections). I covered all 3 parts. hustlin247 wrote:
You probably have this covered but i replaced the rusty corroded blocks of lead that were my battery terminal connectors with tsunami gold clamps and I gained a half a volt.
That's probably a good idea. I do have standard lead-ones. I bought all 4 new (2 for each battery) and i've been using them since the start so I don't see how they could just start adding resistance (.4volt) after adding fuses but mainly removing 5ft worth of wire. -Thanks everyone. ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
Posted By: Alpine Guy
Date Posted: June 25, 2007 at 6:51 PM
How are you testing this voltage drop? The only real way to test it would be use a digital multi meter at the connection at the battery and also check it at the end of the line. If your relying on a voltage display on a distrobution block or a capacitor don't even think thats close to right.
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2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.
Posted By: jmelton86
Date Posted: June 25, 2007 at 7:09 PM
I was using the display on the cap (just recently removed it. I added fuses before cap removal -that's the only way I noticed the significant drop, from the cap display). I've heard that they can be over-inflated by .3 - .7v but I verified that it was accurate by using a DMM at the cap terminals, surprisingly it was actually pretty close - over by .1 -.2v. ------------- 2013 Kia Rio -90a alternator
DDX470HD GTO14001 GTO1014D (x3)
Big3 in 1/0G
1/0G to GTO14001
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