Switched live near rear light cluster

[Panda]

Hello all,
A while ago I wired a 12N socket to my 406 Estate (2003) by splicing into the various light cluster cables via one of those muti-way towing relays. I took the main live feed from the spare fat 12V live wire that Peugeot helpfully fitted into the loom. This fat 12V wire becomes live when you insert Fuse 15 in the passenger compartment fusebox (next to the BSI). The 12N socket works fine.

Now we have a caravan (watch out for imminent posts about clutch problems) and I've fitted a 12S socket using the same live feed via another inline relay. The problem is that I want the 12S to only be on when the engine is running (or at least when the ignition is on) so I need the fat live wire to be ignition switched. I can either do this using a second relay in the viscinity of the rear light cluster or by changing the wiring around in the fuse box near the BSI. I prefer the first option but can't find any cable in the loom that is only live when the iginition is on. Haynes manual doesn't help. Can anyone suggest easiest way to do this?

Thanks

[DaiRees]

Errrm, I know the fag lighter fuse has 2 positions so that you can make it either permanent live or ignition live depending on your requirements, might be worth checking if the fuse you're using has the same feature? Bit of a long shot I know.....

[Doggy]

I think the nearest feed switched by the ignition is going to be the fuel pump supply - you could probably connect your relay coil to the motor supply & switch the towing socket battery +ve with that. Take care to get the motor supply & not the level sender. (Don't know which car you've got, but I assume it'll have a combined lift pump/level sender unit - wire no. seems to be 1201 grey on all models).

[mjb]

I'd just run a wire back from the cigarette lighter socket and slap a relay in

[Panda]

Thanks guys,

Assuming I can find a sensible cable route I'll connect to the switched live on the wiring for the in-tank fuel pump. The fuel pump comes on for a few seconds when the ignition is turned on and then goes dead again unless the engine is started (HDi). I've decided to use a timer relay that only energises after a preset delay (e.g 30 seconds) instead of a regular relay. That way my 12S socket won't become live until a few seconds after the engine is actually started rather than when the ignition is on but the engine hasn't yet been started. My rational is that if the car battery condition is marginal the last thing you want is to be pulling another 10 amps or so from the fridge and/or battery charger in the caravan when you most need the juice for the glow plugs and starter motor.