SC400-V8

iTrader: (1)

The amplifier on my 92 SC400 just went dead a few weeks back. all sound completely stopped, even tho the radio still turned on. I installed an old nakamichi amp that i picked up years ago in anticipation of this to find it had one bad channel: the right front speakers work but sound wicked static-y, all other speakers work fine.

So, I sent the completely broken amp to a company that rebuilds them and just got it back, I just pulled the "one bad channel amp" and replaced it with the rebuilt one and foudn the radio wont turn on.....

I pulled the battery cables to reset the car, and then tried again... nothing. No radio at all. I then switched back in the "one bad channel" amp to find the radio wont turn on with that either.

What the hell is wrong? All plugs are secured ... is a fuse blown or something?

SC400-V8

iTrader: (1)

Ok, it was the radio fuse... a type20 fuse. I opened the fusebox and looked, and sure enough it was blown. I replaced it with the spare type 20 fuse.... and a second later, i heard a pop. This fuse also blew up.

So, I disconnected the battery, went upstairs and got my only other spare type20 fuse... I plugged the fuse in and reconnected the battery, it popped and another fuse is blown.

Did they rebuild the amplifier wrong?

Big Mack

iTrader: (1)

Probably, but check the wiring to ensure nothing after the amp is shorting out. If it is, there's your culprit. You may have an issue with that RF speaker you spoke of.

Big Mack

SC400-V8

iTrader: (1)

the nakamichi system in this sled is proving to be a very difficult beast to fix. As of this point, I have purchased and received the passenger door side midrange and tweeter, and installed then yesterday. I unplugged the radio fuse before i did this. At the conclusion I put the fuse in, made sure everything was connected and powered it on. The stereo was the same... all speakers functioned fine EXCEPT the passenger doors, which were the ones that were messed up to begin with, they sounded static-like before too.

I then switched back in the rebuilt amp that I tried out before. Before, It powered all the speakers fine, except the passenger door (which didnt work at all) and after maybe an hour, all the sudden everything just cut out and produces loud thump/click noises. This time, just the loud thump/clicking noises.

At this point I have no idea whats wrong here. I can send the rebuilt amp back and have it rebuilt again (lifetime guarantee) but it would seem the passenger door speakers have some problems, even when I switch them with working ones....

Big Mack

iTrader: (1)

No. You switched them out with working units? Are you sure they were working? Did you bench test them with the amp? If not, then you need to. If you get them working on the bench, then install them in the car with that amp, all signs are that the space between them is the problem (AKA, the wiring). I would strongly suggest getting a friend to help and checking the wires for shorts/continuity. Easily done with a battery and a multimeter.

Big Mack

SC400-V8

iTrader: (1)

Alright, new update. I checked all grounds and found the ten-prong plug that goes into the amplifier on the long-side seems to have some pretty nasty corrosion on 3-4 of the ten plugs. The amplifier doesnt have any corrosion on any of its prongs that go into it, but the wiring harness does.

This is most likely the culprit, not the amp or speakers?

I tried to remove the harness to use jellied-rust eater and sandpaper to clean it up, would i be better off buying a new harness? if so, anyone know the part number, where to get it?

SC400-V8

iTrader: (1)

At this point, I used jellied rust remover and cleaned up all the corrosion (there wasnt much at all) on the 4 contacts... I then used some dielectric grease and plugged it all in.

Problem remains, all speakers work fine except the passenger door with sounds fuzzy and scratchy as usual.

At this point, I have absolutely no idea what the problem is, I can send back the amplifier to get it rebuilt again.

Big Mack

iTrader: (1)

I said it before, mang - if the replacement speakers worked before, and everything else remained the same, it's the wiring between the amp and the speakers since you changed the amp. If you know the leads coming out of the amp, test just the speakers without using the factory wiring. It's got to be in the wiring, based on what you said before. It's the only component that hasn't changed.

Big Mack

SC400-V8

iTrader: (1)

As of right now, I removed the amplifier entirely... my antanae seems to be damaged and needs help to deploy and retract, a mess.

When I was driving around today I noticed some crackling sounds coming from the rearward speakers, even when the car is off or on.... what in gods name is wrong with this thing?