Escalating electrical problems...so what's new?

[Les Barbeux]

Hi all,

M.O.T. coming up so I have to get to the bottom of this.

First the front fog lights decided that they didn't want to work.

Secondly a couple of weeks later the info centre started playing up (nothing new there then!) by occasionally reseting itself and going through the start up sequence, then a couple of days ago it didn't come on at all at first and then continually flashed all manner of strange figures on most of the sections in turn. This all seems to be intermittent though, as most of the time all is well.

Now the rear wiper is playing up.....it does not go through the full sweep and goes maybe a third of the way through its sequence then pauses and then another third and so on.

Re the fog light, obviously the first thought is a relay, though I could I suppose, take them out for the M.O.T.!

Re the info centre, as the problem is intermittent my first thought is a bad connection somewhere.

Re the wiper, mmm! who knows!

By the time the wiper started it's games then I started thinking that these problems could well be connected!

Your thoughts on this would be most welcome!

It's not that our quirky vehicles actually have "problems"...they have "characteristics!".....though mine certainly does have "foibles!"

Regards,
Trevor

[Van]

The wiper might be a bad cable, and this can give side-effects. Though not said yours.

[Captain Slow]

Infocentre is likely to just be connections on the instrument cluster-take it out and give them a clean, particularly the metal pins connecting the infocentre unit to the PCB.

Rear wiper is most likely a damaged loom where it bends/moves as the tailgate opens-does the high level brake light operate correctly? If not then maybe CEM or switch on the stalk?

Foglight-could be the switch on the dash not sitting correctly, or anything really...

Good luck with it all!

[Les Barbeux]

Thanks both....
the wiper problem was indeed the loom entering the back door frame, a quick wiggle of that and it worked again....soaking wet too. Soldered the wires where they seemed iffy, found a suitable piece of plastic tubing to encase the cables and to replace the soggy covering....job done!

The fog lights did have a faulty relay as I suspected....though I must admit that I had to check the wiring diagrams in Haynes to verify that these lights did not go through the ECM! Picked one up from the local UNIPART depot...cheap as chips too (forever the Yorkshireman!).

The Info centre however....mmm! that's a bit of a job to get at! cleaned off the connectors at the back. Not sure whether that has cured it yet as there was nothing obvious....time will tell there.

Perhaps it was my paranoia in thinking that they were connected after all???

But now the Rear screen demister has packed up! After replacing the switch cluster it worked for a second or less and then didn't! Obvious thought was a fuse...not that (and by the way, my Haynes fuse list bears no relation whatsoever to the real thing!). Revisited the loom at the tailgate....can't see anything wrong there....checked the switch cluster again, nothing found, and when I manually shorted the switch contacts there was nothing either............will have another go tomorrow.

Meanwhile, any further suggestions would be gratefully recieved!

Regards all.

[heavend]

There's an earth connection in the left rear corner. You have to take the trim out to see it. Water leaking in (and don't 480's leak?! I thought the Dutch knew how to control water!) follows the wiring loom and rusts the terminal post badly. The poor earth can affect rear lights, rear wiper and window heater.
There is two plug in connectors for the rear window electrics inside the ceiling lining, just a few inches from where the cable enters the body. You said water had got into the grommet - I wouldn't be surprised if it had followed the cable and corroded the connectors.
Finally, I've had issues with the blades on the demister switch not connecting with the contacts on the dash. Clean & align carefully to remedy. You can test this by having the switch out and jumpering the contacts with a test lead and see if the heater then works. (oh, you've done that. Great thinking!)
The electrical schematic downloadable from this site is a great aid to faultfinding electrical faults.

[glasgowjim]

heavend you have a pm

[pgmm]

Problem with rear demister solved? And how?

Mine is permanently on, as soon as the engine runs that is... I am going to replace the CEM.

If you manually short the switch contacts, does the indicator in the dashboard light up? Do the door mirrors warm up? The latter can be checked by carefully prising off the mirror glass and checking for 12V over the connections on the back of the mirror glass.

I would not suspect the earth connection in the back of the car if nothing works - rather, check the CEM.

You don't mention what year/type your 480 is. Mine is 1986 and has CEM I - my demister is controlled by CEM connection A20 (which is connected to earth when the switch is operated) and the effect is connecting B1 (+12V from fuse 15) to B3. Should you decide to repair your CEM: the relay responsible in the CEM is the one closest to the B-connector.