Help troubleshoot Sony 504 Amp.

Cass

As per the title i need help. I'm out of my depth when it comes to electronics.

The car came with a Pioneer radio installed and the previous owner gave me the original OEM radio he removed. The is equipped with the original 4 speakers (two front, two back), and two speakers in the rear window shelf installed by the previous owner.

He also installed a Sony Xplod, 504z, 500w amp. It is wired to the cars own audio system, the front and back speakers as well as the two in the rear window shelf. The cars original radio will run only the cars original speakers, but the Pioneer runs all the speakers (original ones and the ones he installed).

My problem is this.

I didn't like not having the steering controls (the Pioneer won't work off the steering wheel controls) so i changed the pioneer out to the car's original radio (which came with the car). It was simple enough. Pull out the Pioneer, slide in the original one, job done.

Roll on a few years and i decided to put the pioneer back into the car and redo/tidy the wiring for the shelf speakers to the amp (as the previous guys attempts were functional, but lacked any sort of tidiness).

Now the cars original speakers work and i get good sound, but the speakers int he rear shelf don't work, and i'e noticed the power/protector light on the amp is not on.

I checked the power and there is 12v going to the amp directly form the battery (the battery fuse is fine), and the two 25 amp fuses in the Amp are also fine.

I then checked the earth and still nothing. So i used a jump lead and connected the earth from the lead to the earth of the battery and still no light on the unit.

So there is power going to the unit it is simply not powering up/working.

Is it knackered or is there anything else i can check.

I'll remind anyone replying that i'm a functional idiot when it comes to wiring to be gentle, talk slow, and where possible use crayons.

Thanks in advance.

TherapyBoy

Is there power at the switching wire when the radio is turned on? You should have 12v at the ‘REM’ input on the amp, this is normally wired directly from the radio wiring harness itself.

Cass

Just after going out and checking it now.

There is nothing. I stuck the multimeter on the power and earthed off the body of the car to check and i got 11.98v. When i move the positive lead of the multimeter to the REM switch i get nothing. Well not nothing, but 0.07v eventually down to nothing.

TherapyBoy

With the ignition on & the radio playing? If so this is your problem. The amplifier needs a heavy 12v live & earth to run, but it also needs a switch normally wired from the radio to tell it to turn on when the radio is on & off when it’s not.

Honestly, if you’re happy enough with the sound you’re getting from the radio through the 4 original speakers I’d remove the fuse from the heavy live running from the battery to the amplifier & leave it disconnected.

Cass

You Sir are a genius. Thank you.

Went out and checked the REM wire. It was in the amp, and when i pulled the radio out the wire was also in the back of the radio. However when i done a better check (laziness and not knowing what i was looking for) and found the REM wire from the amp was there but not connected to the radio. I stuck a spade connector on it, plugged it into the radio then plugged the wiring loom into the car (as well as earthing the large earth to the amp) and hey presto, amp powering up.

Now the even better news.

This was obviously not done by the previous owner (i'm assuming) because i removed the Pioneer when i bought the car and the REM was taped to other wires from the amp but never plugged into the radio so it was never connected and that means the speakers in the shelf have never worked. After i got power to the amp I played around with the settings of the radio and amp and now i have all 6 speakers working.

Thanks so much for the help. This has wrecked my head for the better part of the evening.