Adnan

hey guys, a friend of mine has a rf 851s amp which ran
perfectly fine all summer long and now it blows fuses within a minute
of use even with the gains pinned down
the amp it self doesnt have a fuse,it jus the one running from the battery
it a 60 amp and anything higher or lesser still blows

any suggestions?

thanks!

jalat

iTrader: (6)

amp might be gone... its just odd that the amp itself is not fused.
check all the ground connections, make sure it grounded properly. thats the only thing i can think of.

Adnan

alright in check into that....is there a chance it could be a blown resistor
or other internal parts?

420guy

iTrader: (5)

As jalat said check the grounds, but also check every other wire going to your amp, power, remote on, speaker wires at the amp and at the speaker ends, etc. Even one tiny strand of wire touching the wrong spot can cause fuses to blow like that. Saw one guy with 1 strand of his remote on wire touching the ground terminal (almost needed a magnifying glass to see it) and it was enough to keep blowing fuses. Has anything been changed recently in the car? Battery, speakers, head unit? New stuff added? HID's, fog lights, neon? Can anything get near the wires on the amp? Could somebody have put anything in the trunk and hit any wires?
Let us know about those things and we will go from there.
Nick

MR2NR

iTrader: (66)

Amps power supply section has probably had it's day in the sun. Like most older Rockford amps, they did not have a built in fuse, so nothing out of the ordinary there. Rockford amps were prone to power supply issues and to some extent output device issues if there was not a good ground, meaning check the ground return resistance to see where it is. Above 1/2 ohm, you have a bad ground and that is more than likely what has led to the amps failure.

Adnan

cool...thanks guys its in a older chevy astro btw
he recently upgraded his alternator and did a big 3 so ill look more into that
also im getting suspicious about the wiring since his other amp (t5002) works but makes a clipping sound ...perhaps there could be an issue somewhere
we'll look into that amp post it

MR2NR

iTrader: (66)

Sounds like the ground return resistance might be higher than Cheech and Chong...

JL Stomper

Could also be a coil problem in one of the speakers I had that problem one time as well and that is what it was. fine at lower volumes but as soon as started to crank it up the one coil would short out and blow fuse in a second..

loudtdi

iTrader: (1)

Exactly, the older ROFO amps did not have fusing, this does not mean they did not need fusing. You should have had a fuse at the battery (to protect the battery & vehicle) and one of proper amperage within a foot of the amplifier on the V+.

In the older ROFO amps 99% of issues were due to bad grounds. The big 3 will not make a bit of difference if your ground potential from the amp location to the battery location (where big 3 upgrades connect to chassis and frame) is crap.

Any higher performance amp I install now gets dedicated power and grounds. I see next to zero problems when installed like this.