Technical Earthing problems 2.8td year 2000

[Matthemedic]

Hello I have a X reg (2000) auto trail Cheyenne motor home 2.8td and think I have earthing issues. Has started fine since I bought it 3weeks ago but today after inserting immobiliser fob and turning key to start I have no dash lamps or fuel gauge and engine just turns. Tried hazards wich didn't work at first but after a weird cracking and buzzing from relay started to work. If ignition is turned on I do get glow plug light come and extinguish as normal but no other lights. Indicators have also stopped working. How ever sometime with ignition turned on if the headlights are turned on you get a glimpse of the normal ignition lights but only flickering for a second. I've removed battery and cleaned terminal and copper greased. Removed a chassis earth just below battery and cleaned and refitted. Where else can I look? I've also strapped a jump cable from negative to engine and chassis but no difference. Help appreciated as lack of manuals available leaves me earth hunting..lol:bang::bang:

 

[Shingy]

I kind of know you would have checked it, but what about the battery itself? Have you got 12.5 to 13.5 volts on the multimeter?

 

[andytw]

Battery -ve goes to chassis. Once there it is picked up in various places. For example the starter and alternator, which are on the engine, get their ground from the engine ground strap. If that was faulty then you would have cranking problems but not dashboard light issues.
The dashboard will pick up it's own ground which, again, if faulty would not affect cranking.
So for you to have so many different problems would require many different earth problems, apart from the grounding cable at the battery itself.
I think I am right in saying the live for the starter goes direct from the battery and all other lives also come off seperately from the battery, so the same logic applies.

IMHO you need to focus on

Battery
Battery terminals
Battery ground connection
Battery live connection

 

[Crossingkeeper]

Your description of the ignition controlled functions failing reminded me of a remarkably similar problem on my 1998 van. It was very intermittent so drove me crazy (the engine stopped when the fuel cut-off solenoid lost power, usually when I put the indicators on) and I couldn't track the issue down until thankfully one day it failed on my driveway!

It turned out to be the live ignition controlled feed from the ignition switch into the loom, a supersize 4-way connector block on the top of the offside wheelarch under the dash had overheated and failed.

There was nothing to see on the outside of the block but I tracked the location of the faulty connector down by following the circuit round with a multimeter.

As Andy says it's going to be a faulty connection somewhere, all you can do is pick one of the faulty circuits and work along through the various points that you can easily access with a meter.

 

[Matthemedic]

Guys thank you so much for your help. After 8 hrs of cable chasing and cleaning every terminal I could find in eventually decided to test fuses in place and found one 15 amp fuse which visually looked fine how ever it was a dud. Replaced it and it blew instantly but for a second my dash did re appear. After an hour of pawing over circuit diagram I found that the fuel filter sensor cables had shorted together and gone brittle. Disconnected the sensor. Replaced fuse and away she went. Couldn't have gone on without your help as it soured me on...Cheers. ..new sensor on order.