SATNAV Screen blank. But I can hear radio!

[Benarchard]

Basically the screen will not come on and there is no power to the MKIV unit in the back or any power to the CD changer.  I checked fuse 73 all fine… Any other ideas.  Weird I can hear the radio and turn the channel over on the steering wheel buttons…

The other day the screen was going on and off but seemed fine afterI let the car for twenty minutes. 

Any help appreciated...…

[X5Sport]

Check fuse 7 as well.  Though with the radio working that would also be OK.

You need to get in the boot to check the cabling into the rack in the left cubby hole.  Satnav and cd changer are in the same stack so it might be an earth off or a wire out.

Look for any signs of water in that area too - leaking rear lights or windows or roof drain channels etc.

Richard

[Greydog]

Video/TV unit ??

[Benarchard]

Thanks guys. So checked fuses again... 73 i think or the 5amp that covers the unit had blown and blew again straight away when I replaced it.  Weirdly the fuse that should be there for the CD changer had bee taken out…

I disconnected the whole NAV MKIV unit and then tried another fuse it still blew so wondering if it is a problem with the head unit and a dodgy connection…

Ill have to have another dig round next weekend and check all cabling.

[X5Sport]

Where is fuse '73' ?  Only 64 fuses in the front fuse panel.  What else is on that circuit?

Have you also pulled the power off the CD changer?  Could be a wiring short to ground causing it, especially as the head and tail are on different power circuits.  Anyone been in the boot or under the back seats recently?

Richard

[Benarchard]

It's actually the 5amp fuse 75 slot in the back that is blowing. Are there some other fuses  don't know about??

[X5Sport]

The main box is above the glovebox - all the other fuses are in there.  It hinges down from the glovebox roof.

Sounds like the problem is in the back as the head unit fuses are up front - Fuse 7.

Fuse 75 has the On board monitor module (down by the battery), CD changer and Nav computer on it.

It will be worth getting the spare wheel out, air compressor dome off (4 nuts) and looking at the area by the battery.  Various modules are in that area.  You might have cable damage or a water leak.  That will blow a fuse very quickly!

Richard

[Benarchard]

Thanks all. I will get wheel out and have a really good look at all the wiring this weekend! I'll let you know how I get on.

[Benarchard]

So I took out the spare removed trim and both the cd changer and the DVD satnav unit. Whilst routing around I found a small ball bearing across two contacts on another plug that was exposed. I also looked at the fuse box and there was a small amount of corrosion where the fuse was blowing so I scrapped this of with a small screw driver and cotton wool bud. All back together and new fuse in and we are back up and running.  Pretty chuffed as didn't fancy shelling out at dealer to have it sorted. Nice to have satnav back!

[X5Sport]

Glad it was easy to fix, albeit somewhat trying looking for the actual cause.

Richard