Classic Cerbera electrics gremlins

[Penelope Stopit]

Chuggaboom said:

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.

I read the post to mean everything is working ok apart from wipe/wash and it was these that were playing up when the battery was dodgy

[CerbWill]

Penelope Stopit said:

Chuggaboom said:

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.

I read the post to mean everything is working ok apart from wipe/wash and it was these that were playing up when the battery was dodgy

Quite possibly. It could mean that only the wash/wipe buttons are unresponsive which points more towards wiper specific fuses, the motor, wiper control box or wiring issues. However there are 4 steering wheel buttons wipers, screen washers, horn, and dip/main beam Apologies if that's an egg-sucking tutorial but I can't see from your profile if you own/have owned a Cerbera. If all 4 buttons don't work it's more likely to be steering ECU related, or the ribbon cable wound inside the steering boss that relays button presses to the steering ECU. The OP states that the wipers had moved and the washer pump was stuck on when experiencing initial issues. They also mention weirdness with the radio. In my car Fuse 7 provides power to the steering ECU & the effect of the fuse blowing is that the wipers and washer pump stick on, the main beam sticks on, steering wheel button's don't work among other weirdness. Therefore lack of power to the steering ECU seems to result in some strange behaviour from it. Add in there being several wiring revisions of the years, and multiple power feeds to the steering ECU (and possibly revision to the control box itself?) and its not unreasonable for different cars to exhibit different but unexpected symptoms of a fuse that at first glance appears utterly unconnected to the issues presented being the cause.

Either way, checking the fuses is easy as they're all in the fuse box in the boot.

[Penelope Stopit]

CerbWill said:

Penelope Stopit said:

Chuggaboom said:

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.

I read the post to mean everything is working ok apart from wipe/wash and it was these that were playing up when the battery was dodgy

Quite possibly. It could mean that only the wash/wipe buttons are unresponsive which points more towards wiper specific fuses, the motor, wiper control box or wiring issues. However there are 4 steering wheel buttons wipers, screen washers, horn, and dip/main beam Apologies if that's an egg-sucking tutorial but I can't see from your profile if you own/have owned a Cerbera. If all 4 buttons don't work it's more likely to be steering ECU related, or the ribbon cable wound inside the steering boss that relays button presses to the steering ECU. The OP states that the wipers had moved and the washer pump was stuck on when experiencing initial issues. They also mention weirdness with the radio. In my car Fuse 7 provides power to the steering ECU & the effect of the fuse blowing is that the wipers and washer pump stick on, the main beam sticks on, steering wheel button's don't work among other weirdness. Therefore lack of power to the steering ECU seems to result in some strange behaviour from it. Add in there being several wiring revisions of the years, and multiple power feeds to the steering ECU (and possibly revision to the control box itself?) and its not unreasonable for different cars to exhibit different but unexpected symptoms of a fuse that at first glance appears utterly unconnected to the issues presented being the cause.

Either way, checking the fuses is easy as they're all in the fuse box in the boot.

You make good observations if I have read it the wrong way and the OP has now got plenty to go on if needed

I don't have a problem with your egg-sucking tutorial, sharing knowledge is what the Internet is best for, I possess a Cerbera wiring diagram but unfortunately not a Cerbera

I have drawn a wheel on each corner of the diagram as this is the closest I will ever get to the real thing

Have a good day

[Byker28i]

The other thing when fault finding wipers is to lift the wiper blades off the windscreen to remove load from the motor. No point stressing it.

[Chuggaboom]

Byker28i said:

The other thing when fault finding wipers is to lift the wiper blades off the windscreen to remove load from the motor. No point stressing it.

Yes did this before connecting the new battery.

[Chuggaboom]

Pulled every fuse in the boot and all Ok.

Found the wiper control unit in the passenger foot well behind the pull out piece of carpet next the the ECU and heater control unit above.

Wiper unit wires are not charred but the unit label showers either signs of heat or simply old age compared to those other units in the boot.

Also found I have no hazards, although indicators are fine.

Next step change big fuse in engine bay and try a wiper unit swap.

[Penelope Stopit]

Penelope Stopit said:

Chuggaboom said:

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.

I read the post to mean everything is working ok apart from wipe/wash and it was these that were playing up when the battery was dodgy

Is this correct or not?

[Chuggaboom]

Penelope Stopit said:

Is this correct or not?

Yes just wipers, wash wipe and hazards NOT working. Think I've checked everything else and they are OK.

[Penelope Stopit]

Ok

The wiper control unit (and wiper motor) will have a green cable to it, check with ignition on that there is or isn't a supply at that cable, there should be a supply from the fuse-box

[Byker28i]

Can you indicate left and right? Looking at the hazard not working, apart from the earth which runs down the 10 pin cable the indicators/hazards run down the 5 pin cable. Common to all these is the steering control box which is velcroed to the underside of the steering column cover, as mentioned earlier.

If the horn etc is working on the steering buttons, it's not power.

http://tvr-cerbera.co.uk/WorkshopWiringDiagrams/St...

It's easy to jumper across the pins on the little connecting circuit board at the base of the steering column to check circuits.
Even easier if you take the bolt out the column adjust and drop the column