Power for heated seats & radio in BS1

[dutchspiderrider]

Hi,

I’m trying to install heated seats in my ‘70 BS1. Seats are done, buttons installed in the glovebox, now I need power for them. Needed is 4*35w , 140w in all. While I’m at it, I also want to install my radio.

So tried to connect them (the red wires) to the switch between courtesy light and cigarette lighter to be able to use them when ignition is off, but also be able to swicht them off. Power from cigarette lighter to the switch. Yellow wire from radio also connected to cigarette lighter for continuous power (memory, settings, etc.). Black wires all connected to black wire of cigarette lighter.

All seems to work untill I put the courtesy light back in the (iron) console: than fuse A burns/breaks.

What am I doing wrong? And am I doing things ok?

Also read following post, but don’t follow exactly (not my cup of tea them wires)
http://www.fiatspider.com/f15/viewtopic ... er#p283767

Any help is appreciated!

[18Fiatsandcounting]

140 watts is a lot, and the heated seats will be the most power-hungry item in your car. Even more than the headlights. If it were me, I'd run a direct power line to the battery with an inline fuse. Perhaps 16 amps as that's a common automotive fuse. The wires would have to be pretty beefy as well, and I wouldn't try to run this through the stock ignition switch as it's just too much current. You might also need to think about an alternator upgrade, to 65 or 95 amps.

-Bryan

[Anbele]

Heated seats!!! …oh my! What would you like to install next!?…power steering!?
Awesome updrade. But as Bryan suggests, a 95-amp alternator is probably required.

[spider2081]

I know there are more than one manufacturer for heated seats. I looked at one recently for a friend. This manufacturer recommended a 10 amp fuse for each seat.
I would not want to add that much additional current flow through an original ignition switch. I suggest you create a new power buss using a relay like the one in this link: https://www.ebay.com/itm/303958724214. Then the ignition switch carries only the current required by the relay (less than one amp) and the relay contacts carry the additional current of the heated seats and radio/entertainment.
Just a thought

[dutchspiderrider]

Thanx for all the suggestions! Will pick it up after the summer. And yes, heated seats can make the season here in Holland longer or at least more comfortable