Positive terminal in engine compartment

[Redline]

Hi!
I'm about to install some gadgets, and I was wondering where the positive terminal is connected in the engine compartment? Also, where is the most practical point to get some wires through to the cabin?

Car is a W202 C180.

 

[Dec]

You could get power from the fuse box in engine compartment but am not sure which is the best way to enter the cabin, alternatively you could get power from the fuse box in the boot, behind battery, much easier to enter the cabin but a longer distance to the dashboard.

The best way to get power in the cabin is from the cigar lighter as the gadgets you connect to it will be off when the ignition is off. All this depends on what gadgets, and how many you are going to fit and how much current the are going to draw.
See… http://www.mbclub.co.uk/forums/showthread.php?t=58144
Dec

 

[Redline]

Thanks Dec! The "gadget" I'm installing is a siren, so the speaker part is going in the engine compartment, while the control box is going in the cabin. Not worried about battery drain as it doesn't pull any power unless a button is held down (NO impulse switch). Is there a contact point beneath or near the fuse box or is it connected inside it? Anyone who knows for sure?

 

[Diesel Benz]

You would have to have the wire fused anyway, picking up an appropriate empty fuse box position or wiring in parallel with some low importance and similar current rating fuse as your gadget needs should be safe (you don't want to lose lights in the dark or something similar if your gadget fails).

 

[Redline]

Yeah, can't argue with that! I was wondering how it was done anyway so I know what to expect when I decide to do it. Freezing outside now and no heated garage to park in, brrr....