peugeot wiring problems?

There is nothing in your question that points to a wiring fault.

Several services do not work.

A short will cause fuses to blow or wires to melt or the battery to flatten. A short might make Service A be controlled by switch B.

You say several fuses are "earthed" - if this were the case they would blow - shorted to earth with no load.

Some services in a vehicle do not operate until the ignition switch has been turned to position 1 - this is achieved by controlling those services by a relay from the ignition switch - this might be a circuit you could investigate - a circuit diagram like in a Haynes manual would help a lot.

If the battery light stays on (with the engine running) then there's a fault with the charging arrangement - not the same fault that you complain about with things not working - if a service is not working - assuming it has a good earth return path - then it has no power for some reason.

You have several services that are not working - it's odds-on that it's a single cause - it might be a wiring fault (not a short) but not necessarily.

https://www.youtube.com/watch?v=ufVuWznmJLA

Other more experience people on here are very scathing about motor vehicle electrics - particularly French vehicles. On here I have seen many references to poorly made dashboards - bad flow soldering and poor inspection - causing bizarre fault symptoms - Renault particularly.

Good luck...

Peccavi
June 2013