Fuses getting FIRE hot...

[LAYLOW]

Ok... here's the background on my setup:

I have a fuse link off my pos from the battery (plastic screw together type) and a fuse block (three fuses) in the trunk with my cap, subs, 2 amps, and crossover (all existing for about 1.5 - 2 years). I have two square 12" Solos in the box and a Punch Power 1000 amp going to them. I have a Punch 800 going to the mids/highs.

I have blown the fuse in the front (fuse link) a few times over the lifetime of having the system and just replaced it no problem. I've also blown a fuse or two in the back fuse block and just replace with no issues. I put 80A fuses in all of the locations I've mentioned.

Here's the current issue:

I got a new Alpine HU to replace my Premier (Pioneer) HU. I installed it and everything was working perfectly for about a week.

I was driving and suddenly everything went completely silent, but the HU stayed powered and the display continued. From past experience, I knew I had blown the front fuse-link fuse. I replaced with another 80A fuse and it blew again as soon as I turned the HU back on (after turning it off and the car off to replace the fuse). I thought maybe I had a dud fuse and put another in there. Everything was cool for a few more minutes of driving and then the bass fuse in the block in the back blew (1 of the 3 is bass). I replaced that fuse (as well as the other 2 just for kicks) with all 80A fuses. I noticed that when I was replacing all of these fuses, they were FIRE hot when i pulled them out, which I don't think is normal.

I pulled the bass fuse out completely and just rode the rest of my trip with mids/highs. Two days later, I put the bass fuse back in and noticed that the bass was not hitting as hard. The front fuse blew again and when I went to check it out, the plastic threads had literally melted to the end cap of the fuse link on one side. All connections to the battery are solid and no corrosion shows at all.

One of the subs was not hitting when I looked at the back while the music was on, and the other was barely hitting. For the time being, I replaced the fuse link in the front and took the bass fuse out and am just using mids/highs now.

This has been fine for 5 days so it seems something related to the bass fuse being in there is causing the issue... any help would be appreciated in figuring this thing out.

Thanks....

Click to read more...

 

[azbass 5,000+ posts]

what size power wire you have ran?

 

[matrxx dude 5,000+ posts]

what size power wire you have ran?

x2

 

[Directed_zane 10+ year member]

I would try goin to a bigger wire...i had the same problems with mine when i had a 6 gauge wire but when i went down to a 4 they it fixed the problem.

 

[da12b 10+ year member]

I would run at least a 1/0 ga wire with a 250A ANL fuse from the battery pos to a fused D-block, then to my amps. Make sure the battery pos to the ANL fuse is a max length of 18 in. On the fused D-block, I would put a fuse to each amp less then the fuse rating of the amp fuse (example: amp rating 75A, I would put a 60A fuse on the D-block).

hope this helps

 

[helotaxi 5,000+ posts]

I would actually recut and restrip the wires going into each of your fuse holders. It sounds like you've had the system in for awhile and the heat is a sign of a high resistance connnection to the fuse holder. Over time the copper wire will oxidize and that will increase the resistance of the connection and cause it to heat up when a decent amount of current is flowing. Redoing all the wire will remove the oxidized section and give you the chance to make sure all your connections are tight. Replace the melted holder while you're at it.

 

[LAYLOW]

I would actually recut and restrip the wires going into each of your fuse holders. It sounds like you've had the system in for awhile and the heat is a sign of a high resistance connnection to the fuse holder. Over time the copper wire will oxidize and that will increase the resistance of the connection and cause it to heat up when a decent amount of current is flowing. Redoing all the wire will remove the oxidized section and give you the chance to make sure all your connections are tight. Replace the melted holder while you're at it.

Ok... but my question on this is why does it only do this when the top (bass) fuse is in the fuse block in the trunk. When that fuse is taken out and I'm just on mids/highs, everything works perfectly, no issues with blowing fuses or anything at all. I am thinking that it could be a bad bass amp or something like that... thoughts?

 

[Safe-N-Sound215 10+ year member]

Ok... but my question on this is why does it only do this when the top (bass) fuse is in the fuse block in the trunk. When that fuse is taken out and I'm just on mids/highs, everything works perfectly, no issues with blowing fuses or anything at all. I am thinking that it could be a bad bass amp or something like that... thoughts?

Could be that when you have your bass amp hooked up you're more than doubling the current draw of when you have just you're mids/highs amp hooked up, which is causing a strain on your electical.

 

[Safe-N-Sound215 10+ year member]

I would actually recut and restrip the wires going into each of your fuse holders. It sounds like you've had the system in for awhile and the heat is a sign of a high resistance connnection to the fuse holder. Over time the copper wire will oxidize and that will increase the resistance of the connection and cause it to heat up when a decent amount of current is flowing. Redoing all the wire will remove the oxidized section and give you the chance to make sure all your connections are tight. Replace the melted holder while you're at it.

I would try that first before going out and buying a new amp.

 

[helotaxi 5,000+ posts]

Fuses only get really hot when there is a bad connection. Otherwise they either pass current with negligible resistance or they blow. Resistance coupled with current is what causes heat. Without the additional draw of the sub amp, there is probably very little current being drawn. I would estimate that your sub amp is pulling on the order of 5x more current than your mid-high amp. 5x more current is 5x more heat produced on the bad connection. It the problem was the amp, the terminals on the amp would be what was melting, not the fuse blocks upstream from them.

 

[LAYLOW]

Fuses only get really hot when there is a bad connection. Otherwise they either pass current with negligible resistance or they blow. Resistance coupled with current is what causes heat. Without the additional draw of the sub amp, there is probably very little current being drawn. I would estimate that your sub amp is pulling on the order of 5x more current than your mid-high amp. 5x more current is 5x more heat produced on the bad connection. It the problem was the amp, the terminals on the amp would be what was melting, not the fuse blocks upstream from them.

Good info... could a failing sub be causing this? When I started going through all of this and I noticed the bass being very weak and cutting in and out, I opened the trunk to find that only one of the subs was even hitting (while very weak). Could the non-working sub be causing what you describe above, or is it more likely a wiring/connection issue?

 

[helotaxi 5,000+ posts]

If it was a problem with the sub, the amp would be lowing fuses, not heating them up. If they are getting hot there is a bad connection. The bad connection could be causing a problem with the amp though. The voltage drops at the bad connection and causes the amp to perform less than spectacularly.

 

[Megalomaniac 5,000+ posts]

skimmin throught thread...i bet he just has his amp bridged so hes pullin way too much current. it happend to me once on my older amp

 

[helotaxi 5,000+ posts]

Pulling too much current blows fuses. Bad connections case excessive heat.

 

[LAYLOW]

Cool... so its pretty much narrowed down to a bad connection somewhere (at least that's what I'll attack first). Can someone tell me the connections that I need to inspect or replace? Between all my stuff in the trunk and then the connections off the battery, I'm not sure which ones you guys are all talking about. Thanks for all the help.