C5 Series 1 Won't Run

[JAJEA]

9

Sorry, I've misled you. I confused the sockets in the diagram and you want to look at the grey socket. GR=Gris=grey. VE=Vert=green.

The pin allocation for the grey socket has the pump fed from pin 11. Pin 12 is empty I expect for the HDi. I think pin 10 will have a wire connected already.

Grey socket:
View attachment 232446

Green socket. Melted pin 16 is listed as being for AC.
View attachment 232448

Black socket:
View attachment 232447

This is a portion of a relevant wiring diagram and you will see pins 8 and 16 on the green socket are joined and supply the cabin AC blower. It was common for the wiring to have a meltdown at the fan module end, but you have this issue at the BSM end. While it already has a relay in the BSM for this, since the pins are already damaged you may need to add another high current relay (F18 is a 40A fuse) into the line feeding the blower to reduce the current being drawn through pins 8 and 16.

View attachment 232449

Once again you have excelled. I've not had much time but did check out those MTPs and in particular the grey one.
Pink #11 [in the grey MTP] is pink (for choosing a colour - it is similar to the black pin #16 that I believed was the same pink cable at the pump).
Checking out this pin's actual terminals they are not silver but we'll and truelly tarnished albeit ever so lightly.
Still busy with non Citroen issues tomorrow but will confirm that this Grey MTP pin # 11 is the same cable at the pump.
Upon doing so, I'll certainly adapt a relay to get those 12Vs to the tank pump for once and for all.
By the by, the heat stressed pins in the green MTP belonging to the AC control module explains those failed Valeo controlers with those pissy little terminals being supplied with far too many amps no doubt
Best regards
John

 

[JAJEA]

Gents, it is necessary for an update on that C5 known here as the "reluctant car" in case fellow Aussiefrogers have a similar problem.
Eventually when I got to it, it was confirmed unequivocally that pin 11 in the grey multi-terminal plug (MTP) supplies power to the fuel pump,
Whilst there was no excessive evidence of heat stress on that terminal like some of the others, I simply cleaned it with "DeoxIT" that I had left over from cleaning BMW E34 instrument panel ribbon cable connections between circuit board and LCD display.
I had used the appropriate sized tooth pickster to clean the inside of all female MTP terminal and scrubbed the male terminal coming out of the circuit with a cotton wads. All to DeoxIT's instructions; ie, first the terminal cleaner, then the Gold terminal enhancer. The male pin terminal "11" was given a slight twist with long nose pliers to increase contact pressure / area upon pushing MTPs home.
After extensive use of the C5 for a week - it went anywhere and everywhere, it was deemed once again reliable.
This weekend, Dandelion Wine (band Australia, with ... band Au, Google goes to the band's Web site) ventured from Melbourne to Annandale NSW in that reluctant car and so far, all is well.
So, I did not need to get a separate or use a relay to supply power to the fuel pump. Whether, it's reliability will continue, time will tell. In any case, I'll know exactly what to attend to.
Once again thank you all.
This C5 is still around even if we have literally replaced it with the Peugeot 508 GT wagon - it is becoming handy to others to scrap.
If it was not for you lot, I'm sure that it would have been dumped by now as many others have been scrapped for minor issues (unbeknownst to original owners).