Speaker issues

[rogerthechorister]

My good Sport has just developed an issue with the sound system - namely no sound out of the places Volvo put speakers (dash, front doors, rear doors and D-pillar). All of them went off simultaneously. Sub still thumping.

This is taking place with three different head units (two different Sony ones and a JVC one. It is taking place with three different ISO-to-Volvo adaptors - and two different Sony-to-ISO adapters and of course the JVC-to-ISO adaptor.

So, first thought - a speaker is short and the head units are protecting themselves. BUT with a multimeter all the speaker wires at the head unit end show about 4 Ohms (as they should).

Odder still, yesterday on my way to shout at Halfrauds (quite unjustifiably) on my drive all head units fine - and the one in the car went quiet again halfway to Halfrauds. All head units test OK at Halfrauds, but none work correctly in the car.

Now to my mind this suggests that somewhere a plug-in connector in the loom is wiggling about (since I've ruled out the adaptors). Is there one, maybe somewhere under the dash? I hate taking the dash out!

Next possibility, a wire somewhere has been rubbing on a metal edge. Insulation worn, intermittent short to earth, head units go into self-protect mode. This will mean removing all the door cards, tracing the wires to the D-pillar speakers, hoiking out the door speakers and dash speakers, and poking things up door pillars until I find the culprit. Bah.

Open to helpful suggestions where to start!