My Kenwood HU was losing output intermittently (or so I thought) so I convinced myself I needed a new HU. I bought a new Blaupunkt HU and installed it today but although the HU recognises all the sources and scans for FM signals nothing comes out of the speakers. I re-installed the Kenwood and it behaves in exactly the same way. What's gone wrong? Should I check the speaker wiring now? Is there a fuse I should check?

 

Have you actually connected the block containing the speaker wires?

 

I have exactly the same trouble. Let me know if you have any luck mate. Im guessing there is a speaker conecting block further into the loom than the standard ISO one. Just off to ask me mates at the local stereo place to see if they have any ideas. Ill let you know

 

Have you changed the speakers ? If so you may have a short, I had one and it shuts down the Amplifier in the Head Unit - check connections to speakers

 

Same problem I had, bought a new head unit and still had the same problem. Turns out the front speaker wires were shorting and tripping the amp out. I just cut the front speaker wires near the plug and and now it works fine(apart from no front speakers) I'm guessing the wires are broke were they go into the door from the A pillar.

 

Yes thats almost certainly your problem. You have a short somewhere in the speaker wiring.

If you have a tester and you know what you're doing then just pull the plug out the back of the HU and test resistance on each speaker + & -. Should be 4 ohms I'd have thought, most are (or poss 8, unlikely to be anything else).

Then test from either + or - to an unpainted metal part on the body of the car (door hinge bolt should be easy if you can't find anything else).

If you get less than about 1 ohm from any pair then thats the speaker(s) thats giving you trouble. You've just narrowed down the amount of panels you need to rip apart in your car

The reason that your kenwood was working intermittantly and the other is off all the time might just be that the kenny has less delicate circuitary and is still trying to feed the short.

HTH

 

Just to add if you measure the resistance of a loudspeaker (i.e. across the + and - terminals) you're likely to get very near a short circuit reading (probably less than one ohm I'm guessing); the 4ohm and 8 ohm impedances won't really apply at DC.

As above, measuring between the + to the car metalwork (i.e ground) and then the - to the metalwork should give you an open circuit reading if all is well.