Hello,
I'm trying to install an aftermarket head unit (ATOTO S8 Ultra) into my 1997 Toyota Chaser. Up until now, the car has had the factory radio and amplifier under the passenger seat.
I purchased a Metra 70-8112 adapter to convert to the ATOTO harness and plugged the RCA cables into the back of the head unit. Once I had it powered up (ignition turned on, car not running), there were a couple of issues:
- The volume is very loud -- having the head unit set to volume level 1 is normal listening level, and anything above is way too loud. From what I've read the RCA jacks on the head unit are line-level, but I ordered a LOC to hopefully have some better control over the levels.
- There is a loud buzzing/whining/interference noise coming from all speakers. The noise seems to react to inputs on the screen, like scrolling and opening apps
On the factory radio, this buzzing doesn't really seem to happen. I did notice that with the volume knob turned almost all the way down, I can hear a bit of it but it's nowhere near as loud as with the aftermarket head unit. Once I have the factory radio at 0 volume or turned off there's no noise, as I'm guessing it turns the amplifier off.
Troubleshooting steps I've tried so far:
- First, I tried changing the radio ground to something other than what the adapter was providing. I even tried grounding it to the case of the factory amp, but none of it had much of an effect
- Next, I disconnected everything and jumped the ACC wire to the amp remote turn-on wire. This brought on the buzzing, although maybe not quite as loud as with the radio fully hooked up. So it seems to me like the issue is not with the head unit, but with the amp. But why would it not be an issue when the factory radio is installed?
It almost seems like the amp is getting forced to max volume, but I'm not sure how that would be possible. The only other options I know of are to bypass the amp entirely or to try and install an aftermarket amp, neither of which I'd like to do if I can avoid it. I may try to remove the amp and open it up to make sure there's nothing physically wrong with it (capacitors seem to be an issue with these cars at this age). Does anyone have any suggestions of how else to troubleshoot this or ideas what could be wrong?
Here's the radio pinout if it helps:
I'm trying to install an aftermarket head unit (ATOTO S8 Ultra) into my 1997 Toyota Chaser. Up until now, the car has had the factory radio and amplifier under the passenger seat.
I purchased a Metra 70-8112 adapter to convert to the ATOTO harness and plugged the RCA cables into the back of the head unit. Once I had it powered up (ignition turned on, car not running), there were a couple of issues:
- The volume is very loud -- having the head unit set to volume level 1 is normal listening level, and anything above is way too loud. From what I've read the RCA jacks on the head unit are line-level, but I ordered a LOC to hopefully have some better control over the levels.
- There is a loud buzzing/whining/interference noise coming from all speakers. The noise seems to react to inputs on the screen, like scrolling and opening apps
On the factory radio, this buzzing doesn't really seem to happen. I did notice that with the volume knob turned almost all the way down, I can hear a bit of it but it's nowhere near as loud as with the aftermarket head unit. Once I have the factory radio at 0 volume or turned off there's no noise, as I'm guessing it turns the amplifier off.
Troubleshooting steps I've tried so far:
- First, I tried changing the radio ground to something other than what the adapter was providing. I even tried grounding it to the case of the factory amp, but none of it had much of an effect
- Next, I disconnected everything and jumped the ACC wire to the amp remote turn-on wire. This brought on the buzzing, although maybe not quite as loud as with the radio fully hooked up. So it seems to me like the issue is not with the head unit, but with the amp. But why would it not be an issue when the factory radio is installed?
It almost seems like the amp is getting forced to max volume, but I'm not sure how that would be possible. The only other options I know of are to bypass the amp entirely or to try and install an aftermarket amp, neither of which I'd like to do if I can avoid it. I may try to remove the amp and open it up to make sure there's nothing physically wrong with it (capacitors seem to be an issue with these cars at this age). Does anyone have any suggestions of how else to troubleshoot this or ideas what could be wrong?
Here's the radio pinout if it helps:
