Left speakers cut out

[Geoz3]

Hi
Car Is 2001 2.5i
In my car I have the cd43 head unit and the original amp in the trunk, also I have the BSW upgraded speakers and integral Model 80.v2 sub woofer run off of an arc audio amp I installed
Also the stereo is The Hi-Fi sysrem with 8 speakers + the sub
Lately it sounds like the left side of the car speakers cut out
I think it is the amp that is shot or could it be the head unit?
When I replace the amp will the CD connection in the trunk still work? as I plan to use the existing wire for new amp
I would like to keep the cd 43 in the car but if it is the head unit that is shot then I would have to replace both
How do I figure out which unit is cause the trouble Head unit or amp

[z3forlife]

It could also be the door wire harness. You’ll have to test with a volt/ohm meter while it’s in failure. It could be any of the 3 possibilities. You’ll really like a new amp’s clarity and cleaner power but I’d verify the problem first.

[BladeRunner919]

Does all the left side cut out, or just the front left? If it's all, I'd be looking for a cause before the amp (HU or wiring), as a problem with the amp would be more likely to manifest as one of the four chanels and you'd lose FL or RL but not both.

[Geoz3]

It could also be the door wire harness. You’ll have to test with a volt/ohm meter while it’s in failure. It could be any of the 3 possibilities. You’ll really like a new amp’s clarity and cleaner power but I’d verify the problem first.

Z3forlife
I thought the same thing but the door harness would not cut all the speakers on the left out would it?

- - - Updated - - -

Does all the left side cut out, or just the front left? If it's all, I'd be looking for a cause before the amp (HU or wiring), as a problem with the amp would be more likely to manifest as one of the four chanels and you'd lose FL or RL but not both.

Bladerunner919
I believe the entire left side cuts out front door ,footwell and behind the seat

[z3forlife]

Yes this sounds like the amp or the head. My bet is on the amp.

[Geoz3]

Update
Check all connections going into amp they seem tight anyways left side seems to be working now
Will investigate more in the spring as I have other things to do right now and it is almost time to put car away for winter so it will get check and fixed in the spring I hope
Thanks for your help