Xantia V6 (Mk 1) Injection fuse

Post by **xantia_v6** » 11 Jul 2009, 19:23

Anyone else had this 25A fuse blow?

I was driving down a farm track at the time, which would have been severely jolting most cars, but the suspension was handling it smoothly...

Interesting set of symptoms after the fuse blew:
* A/C fan kept running when the ignition was switched on even though the engine was stopped.
* Imobiliser LED both off when ignition switch on, but both came on a few seconds later, and both remained on after code was entered.
* Transmission locked in P.
* Could not hear fuel pump (clue for checking fuses).

I had a quick look around the engine, but can't see any damaged cables, and the car runs again with a replacement fuse.

Post by **xantia_v6** » 31 Jul 2009, 18:14

Update...

I commuted to work in the car for a week with no problem, then on the next weekend the same fuse blew. Then another week of commuting and not problems, then off to France on holday...

Just pulling into a parking space a Eurotunnel, and the fuse blew (persisting down wih rain). Put in another fuse and it blew when selecting reverse to get out of the the parking space. Replaced the fuse again, removed the engine cover, started the engine and poked and prodded all the visible harnesses, no problem, got in the car, foot on the brake to select reverse and fuse blows again.

So three fuses blown without moving a metre... not looking good for the 400 miles left to travel that day.

Replaced fuse again, started engine got under car (still persisting down) and pushed and pulled the fuel pump harness, no problem, more pushing and pulling of harnesses around engine, no problem.

So select reverse, no problem, drive around the car park a couple of times, no problem.... Decide to be brave and continue the trip...

400 miles that day and another 200 odd since, including an assortment of cobbled and unsealed roads, and no further problem. Frustrating? YES.

The only common factor in the 5 occurences of fuse blowing are that on eac occasion the car has been travveling at less than 5 MPH or stopped, and on every occasion I have had the brake applied, but I can't see how the brake circuit is connected with the injection circuit.

Jim has supplied the appropriate set of wirng diagrams, but they have not helped much, as all of the injection and ignition, and the cruise control seem to go through that fuse == a lot of components and wiring.

For now I will just wait and see, and keep an box of 25A fuses on hand.

Post by **myglaren** » 31 Jul 2009, 19:06

The only common factor in the 5 occurences of fuse blowing are that on eac occasion the car has been travveling at less than 5 MPH or stopped, and on every occasion I have had the brake applied, but I can't see how the brake circuit is connected with the injection circuit.

May not be true of your car but on mine I believe that operating the brakes also cuts the fuel (not altogether and not on idle, naturally) so there could be a connection there.
For it to blow a 25A fuse seems rather suspicious though unless there is a short to earth there somewhere.

How about selecting reverse? That sounds as though it has tripped it on at least two attempts.

Post by **CitroJim** » 02 Aug 2009, 18:24

This has to be, in some way, connected with the Park interlock solenoid as this is when the fuse seems to like to blow and this is where I'd be inclined to start my search.

The brake pedal feeds to this, the engine ECU, cruise ECU and gearbox ECU. Somewhere and under some condition, the supply must be finding an earth to pop the fuse. Remarkably, those 20A fuses don't take a lot to pop them. They are certainly "quick blow".

Is there any other circuits diagrams you need to help you? Let me know and I'll scan them up

Post by **xantia_v6** » 02 Aug 2009, 19:18

Back home now, no further incidents.

I will take a couple of hours and carefully inspect the wiring again.
I was wondering about the brake pedal switch, which has cruise control wiring, but I don't think it has a convenient earth point.

On a lighter note, when I am driving the E-type in Europe, people often strike up a conversation at service stations, to talk about my nice classic car, and how they either always wanted one, or had a friend who had one...

Well today in France at a motorways services, a Dutch man came over to talk about the Xantia, how he owned one (a V6), and loved the ride, but sold it because the repairs cost too much...

Maybe the Xantia is getting classic status??

Post by **CitroJim** » 02 Aug 2009, 20:00

xantia_v6 wrote:Back home now, no further incidents.

That's good news! Maybe the car does not like it's homeland

xantia_v6 wrote: Maybe the Xantia is getting classic status??

In the case of the Activa and V6 particularly, if not already, they surely will be in the near future.

One day, the world at large will realise what they've been missing all these years.

It's happening with the BX as we speak

There is nothing nicer than to have an impromptu natter witrh someone enthusiastic like that. Can't work out why he found the V6 expensive to repair though

(tongue firmly in cheek). I think it was Stempy who used to call his a "Money Pit" in his signature...