I started up my car yesterday and noticed that the rear speakers wern't working. So today I go out the multimeter to try and source the problem and found the power at the amp was almost non existant(0.6v). So I started at the battery terminals and began to work torwards the amp. Here are my readings(all back to the neg terminal unless otherwise stated):

pos terminal 12.8v
amp lug conected to pos terminal 12.8v
input side of fuse block 12.8v
output side of fuse 12.8v
output side of fuseblock 0.6v!?

Now, I've checked the fuse and the output conecter and both visualy look brand new, no corosion, nothing. So what the hell is going on?

For reference this is the fuse block in question
http://www.wiringproducts.com/contents/media/l_fpc1g%20fpc4g.jpg

High resistance join in your output side fuse block, check to see if there is any corrosion inside the fuse holder and re-terminated the cable into fuse holder.

High resistance join in your output side fuse block, check to see if there is any corrosion inside the fuse holder and re-terminated the cable into fuse holder.

Please refer to the original post:


I've checked the fuse and the output conecter and both visualy look brand new, no corosion, nothing.

Yeah mean bumpkins. I have seen many people over look simply faults.

You can have a good looking joint but still have a loose terminal screw or not a good electrical connection. On all electrical products it says that you should check all electrical connection before you power up.

Also doesnt mean a person hasn't screw down on the outer insulation of the cable causing a hi resistance joint or a bad fuse holder unlikely but can happen. Re-terminated the cable into fuse holder and also check to see if the fuse fit in snugly into the holder. It sounds like a high resistance join or a broken cable but from what you said it something to do with the fuse holder.

Voltage cant just vanish for unknown reason there could be a break in the wire, or a high resistance join.

Those style fuses are most commonly blown in the caps. They will not show visual indicators.

He tested the fuse output for voltage and was fine. Im going with bad connection and or materials in the holder itself. Try replacing it lol Aerpro are known for doing it

A lot of fuses and fuse holders go open circuit where the wires join the end caps. Junk and replace.

Have spent the afternoon buffing and polishing all parts involved just in case( but to no avail) and will replace the imediately following cable tomorrow as well

Try a temporary bypass of the fuse and holder to see if this fixes things.

So after a week camping I have found the problem. Even though I couldn't see any corosion on the fuse holder I decided, while out camping, to clean/buff/polish the bajebus out of the fittings to the point where I had removed the gold plating from the cast metal. And low and behold a spider web of corroded cracks so fine i could only clearly tell what they were under a magnifing glass :S and with that mystery solved I spliced the cables together(gotta love cable-ties) and drove home fuseless but tunes a-pumping.

So after a week camping I have found the problem. Even though I couldn't see any corosion on the fuse holder I decided, while out camping, to clean/buff/polish the bajebus out of the fittings to the point where I had removed the gold plating from the cast metal. And low and behold a spider web of corroded cracks so fine i could only clearly tell what they were under a magnifing glass :S and with that mystery solved I spliced the cables together(gotta love cable-ties) and drove home fuseless but tunes a-pumping.

Fuseless?? :O

Not a good idea at all. .

Fuseless?? :O

Not a good idea at all. .

Calculated risk. The main power is fused at the power block near the amp in the boot as well as at the battery (which is the one I'd removed). And the amp has an intergrated fuse in the unit. Fuseless was a bad choice of words on my part.

Yes it a fuseless system as the fuse near battery will cut out and protect your car from damage, the fuse near the amp protect the amp :P So if that power cable shorted out there is no real safety protection and your car could catch fire. You need to install a fuse holder back near the battery for safety sake :/

Nice additions Sevo and Sparky.
Calculated Risk, it was just the trip home and driver was aware of the shortcut, and would be prepared in the case of incident, its not long term or anything,

Sparky, its a legal requirement too, power runs throught the firewall must be fused in the engine bay, often overlooked by some wiring decks directly to the battery. Accs or attempting to solve noise in the system.

Calculated Risk, it was just the trip home and driver was aware of the shortcut, and would be prepared in the case of incident, its not long term or anything,

This.

those 5AG glass fuses are garbage, so are those fuse holders with grub screw termination. A bolt down fuse and holder which uses the same bolts that secure the fuse to terminate as well are the best, with lugs soldered onto the cables. Something like an ANL fuse, but more robust, like a Littelfuse/Bussman MEGA fuse or even their MIDI fuses and holders. Will post a pic of mine.