Welding a multiplexed car....

Unread post by **RichardW** » 30 Apr 2010, 20:55

Not impressed....spotted some peeling paint /dark spot on the NS sill of the Picasso (this is a 2003 car, just 7 years old). Was thinking it would just be peeling a bit as my old Xantia did, but no, it's rusted through

A quick poke made a small hole, but thumb pressure reveals an area about 6" round that is distinctly crusty. So patch is going to be needed I guess - won't pass an MOT like that! No damage apparent, and it appears to be rusting from the inside out. To hide it properly will be expensive -it's a painted sill, not an undersealed one. So, probably just DIY, grind the welds flat, and blow it over with a rattle can

Then chop it in....

Anyway, any experience of MIGing multilplexed cars? Just drop the battery off, following the normal procedure, and away you go?

Citroenmad · Unread post by **Citroenmad** » 30 Apr 2010, 21:03

Sounds as if there might be a bunged up drain hole somewhere?

Ive had this before on a car, the drain was bunged (with the missing cap from the washer bottle top) and over time it caused the sill to rot out.

Ive never seen a rusty Picasso, cant imagine its normal.

No idea about welding a plexed car though, i asume its just as normal.

citronut · Unread post by **citronut** » 30 Apr 2010, 21:57

cant you just bung a surge protector across the battery, like i do whilst weldding other cars, they dont cost a lot of dosh and dont have a lot inside of them,

im sure Jim will sudgest what component/s to use instead

regards malcolm

handyman · Unread post by **handyman** » 01 May 2010, 06:04

Hi Richard, I would suggest not only disconnecting the battery, but also the connector plug to the alternator and all the ECUs as they will all suffer if there is a surge or spike that runs to earth in the car.

I know its a pain, but I always disconnect any sensitive electronic units in a car before commencing any electric welding. It only takes a few milli-amps and the component is toast. A nasty shock then follows when you find out the cost of the replacement parts.

Handyman

Clogzz · Unread post by **Clogzz** » 01 May 2010, 14:25

Was thinking of earthing the positive battery lead.

wheeler · Unread post by **wheeler** » 02 May 2010, 14:04

Doesent it have a 12 year anti corrosion warranty for corrosion from the inside out ??

Unread post by **RichardW** » 02 May 2010, 20:40

wheeler wrote:Doesent it have a 12 year anti corrosion warranty for corrosion from the inside out ??

Well, probably, but I've no idea when it was last near a dealer for an inspection, so I doubt it's valid - no harm in phoning them up to ask I suppose

Unread post by **RichardW** » 03 May 2010, 08:08

Looks like it should have had an inspection last year at 6 years old, which it certainly didn't. Will be to my account then

Still I managed to re-fix the exhaust heat shield yesterday which has stopped it rattling like a demented cement mixer every time you reversed it

BTW - Citroen are still knocking Xsara Picassos out new - only 2 models available, 1 Derv, 1 petrol. The Derv one (Hdi 90, VTX+ or somthing) has a list price of nearly TWENTY GRAND!!!! Who are they trying to kid?????