Getting power to the back of a Peugeot 406 estate [2004]?

the issue is trying to get a cable through the bulkhead - i can't seem to find a grommet to use as the only thing i can find - high up- is a small cable [6mm?] on the far left [looking into the engine bay-] high up and just before the drivers side wing. Can someone tell me specifically, where there is a grommet/hole to get through the bulkhead.

it was my dad's car and he has just passed away - i need to treat this car with the ultimate respect and care - there is no way i can risk damaging it in any way by drilling a hole "blind" in case i hit something the other side or add an "open wound" for rust to get in

As a compromise, is there anywhere i can "tap" a 35/40amp supply inside the car I'm not usually a person to compromise but in this case [see last paragraph] I would rather bin the caravan than mark the car in any way.

Has anyone tried running a cable under the car? are there enough attachment points?

If you want to draw 35 to 40 amperes from the battery, you'll have to use 10 guage wire minimum. And if you dont want to drill holes here and there, YES you can run a wire underneath the car.

I have experience running 10 guage wires through the "firewall" for an ammeter on the dash. And I used a rubber plug behind the radio area. I encountered insulation and had to stand on my head under the dashboard to find my own wires.
But underneath the car, just follow a Brakeline. Attatch your electric wires with NO SPLICES to the brake line with plastic ties. DONT spray it with undercoating, because you will always want to see rusty brake line areas if they develop.

Once you reach the rear of the car, just use any frame point to attach wires. Maybe someday you will remove these wires easily by just cutting the plastic ties?

You can buy a DUAL BATTERY CHARGER. If you buy a second 12 volt battery, the alternator will charge battery #1 first, then add its surplus voltage to battery #2. I bought this item years ago for a camper/toyota that I had.

Thank you. If you drill a hole in the firewall, make it as low as possible. Then you can see your hole and wires coming through. Up too high, and you will be hidden by dash, insulation, etc. Don't worry about hot water affecting plastic wires, try NOT to let touch of course. Report It

The rubber water pipes go directly into the metal heater core. Don't drill in that area of course. OR... just stay Under the car like I suggested. Rain water won't affect a long plastic-coated heavy wire. Report It