Ah FFS!!!!!

Now only playing anything from the passenger side tweeter!

Anyone got any ideas as to whether or not it's the amp packing in?

 

Aaaannnndddd, in desperation I pulled the 30amp fuse from the dash to check if it was intact, it was, but when I re-inserted, boom, everything now works!

Put a new 30amp in, but I'm kinda confused as to how a fuse would gradually give up the ghost over a few weeks though???? Very strange!!

 

I fkn give up.....................It's now stopped playing the driver side front and is playing the driver side rear speaker.

Does anyone know if this is symptomatic of an amp giving up, it's driving me fkn crazy now at this stage.

 

When did this problem start, did it coincide with any work on the car?

You mention you checked all the wiring? Electrically tested or visually tested?

Does that mean you have a multimeter of some kind and are familiar with DC voltage and current measuring?

Do you have the wiring layout for the audio system?

if you have truly 100% ruled out all potential cable / ground / and supply problems. Then you can certainly consider internal audio equip problems.

I am assuming that removing and refitting the fuse again, does not this time temporary clear the problem? The 30A fuse you pulled, does that just power the sound system?

I guess it is possible that there is a bad high resistance connection on the fuse box side of the 30 amp fuse that makes the amp do weird things due to low voltage. Wiggling it actually made the difference. That should be easily tested by measuring the actual + voltage at the Amp side to a good ground. Also putting your voltmeter across the fuse and seeing what (small) voltage you get across the fuse. There are charts on the web that will give you a good idea of what small voltage to expect under normal load conditions. This test is often done to locate the source of low level parasitic battery draining problems, but I higher voltage reading than normal at low current in the circuit will also suggest a bad connection either in the fuse itself or the circuit itself.

 

When did this problem start, did it coincide with any work on the car?

You mention you checked all the wiring? Electrically tested or visually tested?

Does that mean you have a multimeter of some kind and are familiar with DC voltage and current measuring?

Do you have the wiring layout for the audio system?

if you have truly 100% ruled out all potential cable / ground / and supply problems. Then you can certainly consider internal audio equip problems.

I am assuming that removing and refitting the fuse again, does not this time temporary clear the problem? The 30A fuse you pulled, does that just power the sound system?

I guess it is possible that there is a bad high resistance connection on the fuse box side of the 30 amp fuse that makes the amp do weird things due to low voltage. Wiggling it actually made the difference. That should be easily tested by measuring the actual + voltage at the Amp side to a good ground. Also putting your voltmeter across the fuse and seeing what (small) voltage you get across the fuse. There are charts on the web that will give you a good idea of what small voltage to expect under normal load conditions. This test is often done to locate the source of low level parasitic battery draining problems, but I higher voltage reading than normal at low current in the circuit will also suggest a bad connection either in the fuse itself or the circuit itself.

It's really bizarre, sometimes it'll play both front mids and bass and won't play rear, and other times it'll play passenger side and rear driver side. The driver side is never played at the same volume as the passenger side and if I put my ear to the to the bass and mid there's a faint crackling sound also. The passenger side plays perfect every apart from last week when it would only play through the tweeter.

The wiring in the door is brand new as I'd loads of instances of the cabling fraying at the point it enters the door, so I put one of those fix kits in it.

I might try cleaning the fuse slot that holds that 30amp fuse just in case residue from previous blowing fuses is impeding voltage in some way.

 

It won't be anything to do with the fuse or its contacts. If it was, all the channels of the amp would work or not work, not just some of them.

 

Many audio output Amps have under voltage protection circuits per channel. It's not impossible for a high resistance condition across a fuse (for whatever reason) to turn off some channels or reduce power to some audio outputs. Unlikely in this case I agree but still possible and worth checking as a matter of course.

 

Don't disturbe the fuse further or clean it yet. If you have an auto ranging meter, just set your meter on DC voltage and probe across the two tiny metal bits on the back of the fuse with it in circuit. With the radio amp powered on and assuming say 6 amps flowing ( but its not critical how much) you would expect to see a very low voltage reading of say 14mv 0.014 of a volt or less (across either the mini 30A blade or if we are talking the larger blade type 30A fuse). If your meter is analogue manual set it on lowest dc volt scale first, then if you don't get movement put the meter on its dc mv range and check again. If the meter goes backwards just swap the probes over.
If the fuse or the connections you can't see behind it are introducing a bad connection problem, you will see a higher reading such as 0.4 of a volt or even a few volts. All this assuming the amp is powered on and drawing some current.
If you get zero voltage across the fuse even if the fuse looks corroded its not causing a problem. Hope that makes sense.

 

Don't disturbe the fuse further or clean it yet. If you have an auto ranging meter, just set your meter on DC voltage and probe across the two tiny metal bits on the back of the fuse with it in circuit. With the radio amp powered on and assuming say 6 amps flowing ( but its not critical how much) you would expect to see a very low voltage reading of say 14mv 0.014 of a volt or less (across either the mini 30A blade or if we are talking the larger blade type 30A fuse). If your meter is analogue manual set it on lowest dc volt scale first, then if you don't get movement put the meter on its dc mv range and check again. If the meter goes backwards just swap the probes over.
If the fuse or the connections you can't see behind it are introducing a bad connection problem, you will see a higher reading such as 0.4 of a volt or even a few volts. All this assuming the amp is powered on and drawing some current.
If you get zero voltage across the fuse even if the fuse looks corroded its not causing a problem. Hope that makes sense.

OK, cheers mate.

 

Right, the system has been running perfectly the past week or so, and I am beginning to wonder is it because of the extended good weather we've been having? I reckon when the rain returns and if the problem returns, water is the culprit somewhere.

My boot is def water tight, I fixed a slight ingress at the passenger side over a year ago which has been bone dry ever since. I'm wondering could a leak at the driver's door or scuttle panel below the windscreen be possibly allowing water in at the fuse panel at the end of the dash????

 

Admitted it's hard to find a fault when it's not there, unless it's a loose connection and moving stuff around re creates the problem. Water is actually a bad conductor at 12 vdc but ingress over time causes corrosion and bad connections. If you are talking about corrosion on the heavy current pos neg side of the circuit I would still expect it to cause voltage drop whether damp or dry. The audio signal side cable connections may be affected differently.
The hardest part is physically gaining access to the connections not the elec testing bit. Either way it does not sound like an internal amp fault.
I would still carry out voltage drop tests as it might reveal a present minor problem that turns into a bigger problem sometimes through vibration damp or temperature change. Without the aid of a crystal ball lol you just have to get stuck in and visually elec go over everything.

 

A late update, it started working correctly out of the blue, and has operated properly for 5-6wks now.

Weird.......

 

Then I guess you may have inadvertently moved a cable connection or ground last time you looked and that cleared the problem. It does not have the characteristics of an electronic internal radio fault. Time temperature and vibration may bring it back, but fingers crossed it stays working.

 

I actually never got the time to investigate it properly, due to work and self-renovation on the house, it literally just kicked in one day and has played ever since, the car is used daily. The only thing I did was was check the amp connector was fully seated and cables weren't loose, I supposed something in there could have shifted??? It's a strange one but hopefully keeps going until I manage to try set up the Alpine amp once and for all!

Cheers for the responses.