4 replies to this topic

[Rekusu]

What ho one and all,

 

For years, I have had an unresolved issue with my head unit.  Went over a bump and it went off.  One way or another, I found that thumping the driver door card speaker area, and it would come back to life.  But it progressed until it would not come back, but there was an electrical static discharge sound  through the speakers.  I posted questions here, but to no avail;  I got a replacement from a breakers and that did not work; I changed mine with a neighbours and his worked in mine car and mine worked in his, but mine did not work in mine.

 

So have not had a radio and had to make conversation with SWMBO.  But sometimes, go voer a bump, or thump the speaker, electrical discharge, the hu goes off, and when it lights up again, it is working just fine.

 

Because of the OSF thump test, I figure there is a wiring / speaker issue inside the door, but replacement speaker and checking the wiring ans still no solution.  But recently it has started to work, so happy bunnies all round.

 

Until yesterday!!!!  The radio was working, and I had to do something in the rear; I closed the drivers door and the hu went off.  But to add a new twist, the display was totally blank, dead and the On/Off button did not change anything.

 

Today, I checked the two fuses F69 and F72.  All fine.  But when I replaced F72, Vehicle ID appeared on the screen but pressing any button is not producing any numbers.  And pressing On/Off will not turn the hu off either.  Furthermore, there is this strange 'heartbeat' from the NS speakers only.

 

 Voice 002.mp3   355.5KB   12 downloads

 

To turn the display and heartbeat off, I have had to pull the hu quadlock; reinsert it and the heartbeat and display is blank.  Hit the On/Off, Vehicle ID and heartbeat reappear, but the On/Off again, will not turn it off.

 

So I am at a complete loss.  Can anyone throw any light on this (I'm going to guess the answer is No)  But I don;t know where to check as everything seems to be working, just not in the way it is intended to.

 

Toodle pip and thanks

Edited by Rekusu, 26 November 2020 - 03:06 PM.

[dojj]

simple things to check:

power to the quadlock?

permanent and switched ignition

make sure there's an earth there too

it sounds like a broken wire in the loom somewhere that's broken over time by chaffing somewhere

in other words, an almost impossible fix

[Rekusu]

I know what you mean, but before this 'new' issue, the problem only existed when I thumped the drivers door card.  Somehow, the impact was sending a 'blast' from the speaker to the HU.  I have checked the wiring and exchanged the speaker, but still the problem existed, until the HU was working and I closed the door!

 

As it happens, owing to a fender bender quite some time ago, and a resultant small dent in the drivers door, I do have another ready to go, complete with the door loom.  Just laziness results in not exchanging it.  But an exchange is planned, along with the door loom.

 

To the best of my knowledge, the quadlock is fine.  Have not had entertainment for quite some time, so not being distracted has improved my driving and given me a renewed appreciation for the sound of a Mk 3 diesel engine!

[dojj]

could it be as simple as the plugs in the door loom were knocked and this lead to a short somewhere?

 

you can twist and then tighten them up again, just don't drop the body connector into the pillar (been there, done that) as it's a bit difficult to fish back out again

[Rekusu]

I have not tighten them recently but I have had the connections off to check the wiring some time ago.

 

Strange thing is, if the HU is in 'working' mode, the Vehicle ID illuminates but inputting numbers does nothing.  Also, the on / off switch may of may not work.  I fell certain the HU is working, but the nature of the switch and no ID input does not seem like a poor connection, but what do I know?