# Issues with 2 new Rockford Fosgate Prime amps going into protection immediately.



## BluFuze (Apr 17, 2014)

I just hooked up 2 brand new Fosgate Prime amps. I took out a good, working amplifier and used the same wiring. Both amps are going into protection immediately. I have a hard time believing that both amps are bad. Here is a rundown of my set up and what I’ve done. 

-14 Fusion using stock radio. I use a line out converter with a remote turn on. I have used this for the last couple of years. 

Pioneer component that worked as of 10/19/19. 

Brand new IDQ 12 that I haven’t listened to yet. 

KnuKoncepts Kolossus ofc 4 gauge power and ground wires. KnuKoncepts distro block and fuses too. 


With all wires connected, amps go into protection. 

I unhooked all speakers and rca cables, still in protection. 

Unhooked both power and ground wires to check for stray strands. Made no difference. 

I get 12.56ish volts at amp terminals with ignition off (testing across + & - ). I get over 14 volts with engine running. 

With remote wire connected, I noticed that the voltage reading drops to about 9 volts. I swapped out my line out converter for a new one and the voltage issue remains. 

If I remove remote wire, voltage goes back to 12.56ish. 

What is the deal with the remote causing a voltage drop? I have a feeling that is the issue, but I’m not sure what’s causing it. The line out converter is right next to the amps, and the wire from the remote to the amps is a short run (less that a foot). 







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## jdunk54nl (Apr 25, 2015)

From the owners manual:
Power/Protect LED – Power LED illuminates blue when the unit is turned on. Protect LED illuminates red if a short circuit or to low of an impedance is detected at the speaker connections.The amplifier will automatically shut down if this occurs.

Procedure 2: Protect light is on.
1. If the Protect light is on, this is a sign of a possible short in the speaker connections. Check for proper speaker connections and use a volt/ohm meter to check for possible shorts in the speaker wiring. Too low of a speaker impedance may also cause Protect to light.

Also from manual: So 9 volts should be ok.

Verify there is 9 to 14.4 Volts present at the positive battery and remote turn-on cable.Verify quality connections for both cables at amplifier, stereo, and battery/fuseholder. Repair/replace if necessary.

So seems like it is something to do with the speaker terminals for the amp to go into protect mode. What Pioneer speakers are you using?


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## THX0849 (Sep 24, 2019)

I would say if you're reading voltage at the amps and when powering up the amps the voltage drops that much, first thing i would check would be a bad or weak ground. Even through you swapped from the old setup to the new, stuff can loosen up and cause voltage issues. Same goes with the power supply side. At least to start with the easy stuff

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## BluFuze (Apr 17, 2014)

jdunk54nl said:


> From the owners manual:
> 
> Power/Protect LED – Power LED illuminates blue when the unit is turned on. Protect LED illuminates red if a short circuit or to low of an impedance is detected at the speaker connections.The amplifier will automatically shut down if this occurs.
> 
> ...




I’m using Pioneer TS-D1720C components and as of 2 days ago, they were working wonderfully. I was powering them with an old JBL 80.2. My JBL BP600 died so I bought these matching Fosgate amps. 

Both amps- R500X1D and R150X2 are both showing red light with no speakers or rca cables connected. 

I thought it was odd that the voltage dropped so low once the remote was hooked up. It’s a steady voltage too, not just a dip. 

Could these amps be more picky about their ground location than the JBLs were? 


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## BluFuze (Apr 17, 2014)

THX0849 said:


> I would say if you're reading voltage at the amps and when powering up the amps the voltage drops that much, first thing i would check would be a bad or weak ground. Even through you swapped from the old setup to the new, stuff can loosen up and cause voltage issues. Same goes with the power supply side. At least to start with the easy stuff
> 
> Sent from my Pixel 2 using Tapatalk




Could it be a poor connection at the battery fuse holder? I’ve had the fuse in and out several times. 


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## THX0849 (Sep 24, 2019)

Anywhere along the chain from the battery to the amp and from the amp to the ground needs to be checked. Depending on fuse holder the legs can spread,the screw that is holding it can come loose, the battery terminal itself etc. Just take your time one thing at a time. Even if you've already checked it, check it again. Can't tell you the number of times I've wanted to bang my head into a wall for "assuming" something was checked only to find out it was missed. 

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## jdunk54nl (Apr 25, 2015)

Check the resistance of your ground. Run a wire from battery to the ground area and check resistance of that wire with your multimeter.


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## BluFuze (Apr 17, 2014)

It was the ground. I had my old amps installed for the last 2 years and never had an issue. The new amps just didn’t like the location apparently. 


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## [email protected] (Sep 3, 2017)

I'm currently running 2 Fosgate Prime amps myself. I have the prime 1200.1 on 2 American Bass 10's that amp runs through an L.O.C in my 08 Caddy Cts with the factory radio. So, the rca's from the l.o.c go to that amp. The other Prime amp is the 300x4 that are connected through the hi level inputs to my mids and highs which are polk audio's. So, as much as I love to have the Audiocontrol LC7i I currently went the cheaper way. Needless to say I don't have any problems with my Prime amps amd they both sound amazing and get very loud. Not sure if you're running rca's from your l.o.c to both amps or what, but installed correctly you will love the final results. Thanks.

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