A funny srory of where electronics can get you,,,,

rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
Elsewhere there has been some discussion on electronics and in particular diagnostics. Read on and wonder!

I was using a Citroen Berlingo van which belongs to the outfit I work for. That had a particularly nasty party trick which caught me out the first time - but I soon got wise.

I was driving it to a customer's site in South London and had just come out of the Blackwall Tunnel. It was chucking it down with rain and I switched the wipers on. I'd been using them earlier before I got to the tunnel.

What happened next was an almost complete electrical failure - all the dials dropped to zero, the dashboard lights went out, the LCD displays blanked, the wipers stopped, and I had no turn indicators, horn or stop lights. Thank goodness, the engine was still running and the main lights still worked - but that was it. I had to pull off onto the hard shoulder and call out the AA. I couldn't see where I was going with no wipers.

Luckily for me, the AA driver was 'old school' (and not far short of my age) and he made a couple of calls - and it seems I wasn't the first. What had happened was that the wiper motor had 'spiked' the dashboard computer and crashed it - and that was dealing with everything.

The resolution was something you'd never guess in a million years - you needed to pull out three apparently unrelated fuses from the fuse board under the dash on the driver's side. This had the effect of electrically isolating the dashboard computer. Wait a few seconds and replace the fuses - and all came back to life.

I got the message and made a note of the location of the fuses. However, to gain access to them meant hanging the lower part of my body out of the driver's door to get under the dash, not so easy as it was inevitably raining. So, the next time, I just stopped the engine, popped the bonnet and pulled off the quick-disconnect battery lead, Waited a few seconds. Put it back. Problem solved. The clock needed to be reset and the radio demanded its anti-theft code, but those could wait....

The eventual solution was to get the dealer to replace the computer board. It was a known problem and dealt with under warranty. No trouble since.

Would a sophisticated diagnostics system have helped me? I don't think you need an answer to that one! Technical description - thoroughly Donald Ducked.

Rog.
 

flecc

Member
Oct 25, 2006
50,676
28,509
Nice one Rog, and paralleled by the e-bikes with a low voltage cutout under high load, which run again only when switched off and then back on again, resetting the controller.

Your problem brings to mind something similar on an employee's Lada years ago. That was also fuse related but baffled me until a Lada dealer tipped me off about the Lada's wiring differences. They have house wiring standards rather than the usual vehicle ones, this done by FIAT to deal with the lack of auto-electricians in Russia at the time. Apparently they were adequately equipped with building electricians who could look after more familiar car electrics!
 

muckymits

Esteemed Pedelecer
May 31, 2011
419
2
When I was an apprentice (back in the mists of time) I was send down to DAF trucks for a weeks electrical course, they proudly brought out a shrivelled up wiring loom from a 6 month old truck. The truck kept blowing fuses when it rained, so the owner got a hand full of 1/4 bolts. sawed the heads off and replaced all the fuses. These were still nicely welded in to the holder :D

And he still wanted it repaired under warranty :rolleyes:

Now those trucks colour codes used to get a few people, earth was brown all the others black :confused:
 

rog_london

Esteemed Pedelecer
Jan 3, 2009
764
2
Harrow, Middlesex
In the slot machine business years ago I used to deal with 'foreign' kit, and the mains colour codes were not standardised at that time.

The Americans still have this one:

Black - live
White - neutral
Green - earth.

Germany was the best, though. Luckily you'll never come across this one!

White - live
Black - neutral
Red - earth

The Americans also had an interesting philosophy when it came to fuses - you protected the power supply rather than the kit you had plugged in - so very commonly an American 'appliance' would have no fuses at all, and the first fuse you might come across would be the domestic board and might be 20-30 amps.

Rog.
 

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