Classic Cerbera electrics gremlins

[Chuggaboom]

So today was the first time that Cerbie's electrics have played up. Went to start after a 20 minute journey with a 4 hour gap.....ignition on.....start, and click, dead ! Totally everything. Tried various so left and returned home to gather tools etc. Arrived at car too find wipers have moved and washer motor going full on. Blip the fob and able to enter. Ignition off kills the washer motor. Try to start and saggy turn over....well no doubt the volts have dropped while I have been away for a couple of hours and things have been consuming the battery. So manoeuvre car,during which the radio starts on its own, and I kill be ejecting the facia, and bump start and after a couple of efforts she runs. I leave running not dearing to switch off. Transfer tools etc and leave. On way home odd smell around 20 mins of running...could be car or something form outside through the window. Arrive at home and put in garage. Open doors and boot and disconnect battery. Where do I start ?

[Byker28i]

as a starter, Big fuse, then earth cable from battery to chassis and then onto the the starter.

Check all fuses in the boot, check battery condition. I had some weird things when the earth cable broke, then also when I lost a cell on the battery. Luckily someone had a fancy battery tester that showed a cell was down.

[Chuggaboom]

Battery is disconnected from the car now and on the accumate directly......if that isn't showing green in the morning then that will be a sign of a dead'n ! Up until now never had any battery issues while using accumate as in always plug in when back in the garage at home.

[Chuggaboom]

Oh apparently there is another important substantial fuse other than the big one in the engine bay inside the cabin......do you know where ?

[Byker28i]

My 4.2 fuses are like this:


I'm only aware of the one big fuse on the back of the engine. Other models, griff, Chim etc have them on the chassis

[Byker28i]

later 4.5's are different again. See this thread for details
https://www.pistonheads.com/gassing/topic.asp?h=0&...

[CerbWill]

There is another big fuse (100A) in the passenger footwell protecting the main power feed from the battery to the fusebox.

[Chimp871]

^

It'll be above the passenger left knee and closer to underneath the dash than your knee you'll have to remove the lower cover. Have a torch handy.

I hope that makes sense.

I'd check the positive and negative battery cables including earth points.

[Penelope Stopit]

Was the smell similar to that of bad eggs?

[RUSSELLM]

I’d charge the battery and stick it back on. If the car starts, test the alternator output.

The modules going barmy, is normally the power going off/on whilst you were trying to crank it. I’d expect them to recover when the charged battery’s back on.

Strange smell in a Cerbera, is probably damp

[spitfire4v8]

Make sure the funny smell isn't the wiper control box and associated wiring burnt out. I've just traced multiple electrical issues on a cerbera for a local garage but the initial issue appears to have been the wipers stopping half way on the screen and burning the control box out, and the wiring

[Chuggaboom]

Well today was far too nice to be inside a garage and had other things to do anyway, but the accumate on charge overnight resulted in turning to green around 10 this morning. Next step then get it load tested.

[Wolvesboy]

CerbWill said:

There is another big fuse (100A) in the passenger footwell protecting the main power feed from the battery to the fusebox.

Another 100A big fuse in the passenger footwell? Didn't know about that one.

[Chimp871]

Its the fuse for the power cable going to the fuse box in boot.

It's good news, if the power cable is corroded in the engine bay you need only replace 2' of cable instead of the whole feed to the boot.

Edited by Chimp871 on Saturday 24th August 10:12

[Mr Cerbera]

Wolvesboy said:

CerbWill said:

There is another big fuse (100A) in the passenger footwell protecting the main power feed from the battery to the fusebox.

Another 100A big fuse in the passenger footwell? Didn't know about that one.

Thanks CerbWill

[Chuggaboom]

So the upshot of the battery test was that it's duff despite a recharge turning green. Basically it would charge but fail when put under load.....a thing that happens to batteries many a time over.....having said that me using an accumate had extended that probable life several times over.

Right, new battery in and connected up......let's see what works......answer, everything except the wipers and wash wipe......no response at all from the steering wheel buttons.

Hnm......where is the wiper control unit ? No haven't checked the fuse yet.....depending on car era looks like 16 or 31.

[Penelope Stopit]

The smell was very likely a faulty cell gassing off, this is why I asked about the bad eggs smell, the thing is......What do bad eggs smell of?

I hope you find blown wiper fuses, if there are no blown fuses there is a chance the wiper motor and or its wiring have burnt out

Edit

Oops spitfire4v8 has already mentioned this

Edited by Penelope Stopit on Thursday 29th August 20:09

[Chimp871]

Chuggaboom said:

Hnm......where is the wiper control unit ? No haven't checked the fuse yet.....depending on car era looks like 16 or 31.

In the boot, pull back Velcro cloth panel on the top lip (just under rear window) and you'll see an array of black boxes. Right side you'll see wipe control box, should be labelled. You may see some burnout in the connections.

As said, check fuses, wiper motor .....

[CerbWill]

Wiper control box is in the passenger footwell on my car (1996). Do none of the steering wheel buttons work, or is it just the wash/wipe buttons that do nothing? If all of them don't work it could well be steering wheel ECU or fuses that supply power to it. In my car Fuse 7 powers the steering ECU so it blowing causes wash/wipe and headlight crazyness and also affects the radio and 1 of the door lock motors. Though how Cerberas are wired up seems to vary depending on the day of the week. Mine is nothing like the manual floating around online; I do note those manuals are 'Revision 3' though and my car being very early is clearly an earlier revision so later cars may experience different issues with the same fuse blowing, and at some point the fusebox was changed to a different type.

It could also be the ribbon cable, but a physical failure of the cable at the exact moment you experience electrical issues is staggeringly unlikely.If its just the wash/wipe buttons then it might well be a fuse blown caused by the motor trying to drag wipers over a dry screen, or the extra current draw could have damaged the motor or control box.

Next step before you go digging around for control boxes should definitely be to check the fuses.

[Byker28i]

If none of the steering wheel buttons work it's related to the ribbon cable coming from the wheel.

On my car, the steering wheel control box is velcroed to the panel that covers the lower steeing column. Wingnut on the rear inner wing under the dash, velcro at the front and a 10mm bolt on the left into the tunnel holds it on, but you should only need to undo the wingnut.

Pull out the two plugs, not the ribbon cable, to reboot it. I had this when I put the ribbon cables on backwards when I had the steering wheel out to repair the ribbon cables.

Or, you've pulled one of the ribbon cables off whilst fault finding. There is a small pcb mounted on the top of the steering column just above where the shafts join which has the ribbon cables into them, from the steering wheel, to the steering wheel control box. Sometimes these are glued on with a hot glue gun, often not if people have been there before. Easy to knock off...

The PCB is mounted on a bracket, you can see it here at the end/top of the steering



And here's the box hanging down

Edited by Byker28i on Friday 30th August 11:12